summaryrefslogtreecommitdiffstats
path: root/remote.c
blob: abb24822beb2a17187d4afa9474dd1c537f078ba (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
#include "git-compat-util.h"
#include "abspath.h"
#include "config.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "remote.h"
#include "urlmatch.h"
#include "refs.h"
#include "refspec.h"
#include "object-name.h"
#include "object-store-ll.h"
#include "path.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "dir.h"
#include "tag.h"
#include "setup.h"
#include "string-list.h"
#include "strvec.h"
#include "commit-reach.h"
#include "advice.h"
#include "connect.h"
#include "parse-options.h"

enum map_direction { FROM_SRC, FROM_DST };

struct counted_string {
	size_t len;
	const char *s;
};

static int valid_remote(const struct remote *remote)
{
	return (!!remote->url) || (!!remote->foreign_vcs);
}

static const char *alias_url(const char *url, struct rewrites *r)
{
	int i, j;
	struct counted_string *longest;
	int longest_i;

	longest = NULL;
	longest_i = -1;
	for (i = 0; i < r->rewrite_nr; i++) {
		if (!r->rewrite[i])
			continue;
		for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
			if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
			    (!longest ||
			     longest->len < r->rewrite[i]->instead_of[j].len)) {
				longest = &(r->rewrite[i]->instead_of[j]);
				longest_i = i;
			}
		}
	}
	if (!longest)
		return url;

	return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
}

static void add_url(struct remote *remote, const char *url)
{
	ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
	remote->url[remote->url_nr++] = url;
}

static void add_pushurl(struct remote *remote, const char *pushurl)
{
	ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
	remote->pushurl[remote->pushurl_nr++] = pushurl;
}

static void add_pushurl_alias(struct remote_state *remote_state,
			      struct remote *remote, const char *url)
{
	const char *pushurl = alias_url(url, &remote_state->rewrites_push);
	if (pushurl != url)
		add_pushurl(remote, pushurl);
}

static void add_url_alias(struct remote_state *remote_state,
			  struct remote *remote, const char *url)
{
	add_url(remote, alias_url(url, &remote_state->rewrites));
	add_pushurl_alias(remote_state, remote, url);
}

struct remotes_hash_key {
	const char *str;
	int len;
};

static int remotes_hash_cmp(const void *cmp_data UNUSED,
			    const struct hashmap_entry *eptr,
			    const struct hashmap_entry *entry_or_key,
			    const void *keydata)
{
	const struct remote *a, *b;
	const struct remotes_hash_key *key = keydata;

	a = container_of(eptr, const struct remote, ent);
	b = container_of(entry_or_key, const struct remote, ent);

	if (key)
		return strncmp(a->name, key->str, key->len) || a->name[key->len];
	else
		return strcmp(a->name, b->name);
}

static struct remote *make_remote(struct remote_state *remote_state,
				  const char *name, int len)
{
	struct remote *ret;
	struct remotes_hash_key lookup;
	struct hashmap_entry lookup_entry, *e;

	if (!len)
		len = strlen(name);

	lookup.str = name;
	lookup.len = len;
	hashmap_entry_init(&lookup_entry, memhash(name, len));

	e = hashmap_get(&remote_state->remotes_hash, &lookup_entry, &lookup);
	if (e)
		return container_of(e, struct remote, ent);

	CALLOC_ARRAY(ret, 1);
	ret->prune = -1;  /* unspecified */
	ret->prune_tags = -1;  /* unspecified */
	ret->name = xstrndup(name, len);
	refspec_init(&ret->push, REFSPEC_PUSH);
	refspec_init(&ret->fetch, REFSPEC_FETCH);

	ALLOC_GROW(remote_state->remotes, remote_state->remotes_nr + 1,
		   remote_state->remotes_alloc);
	remote_state->remotes[remote_state->remotes_nr++] = ret;

	hashmap_entry_init(&ret->ent, lookup_entry.hash);
	if (hashmap_put_entry(&remote_state->remotes_hash, ret, ent))
		BUG("hashmap_put overwrote entry after hashmap_get returned NULL");
	return ret;
}

static void remote_clear(struct remote *remote)
{
	int i;

	free((char *)remote->name);
	free((char *)remote->foreign_vcs);

	for (i = 0; i < remote->url_nr; i++)
		free((char *)remote->url[i]);
	FREE_AND_NULL(remote->url);

	for (i = 0; i < remote->pushurl_nr; i++)
		free((char *)remote->pushurl[i]);
	FREE_AND_NULL(remote->pushurl);
	free((char *)remote->receivepack);
	free((char *)remote->uploadpack);
	FREE_AND_NULL(remote->http_proxy);
	FREE_AND_NULL(remote->http_proxy_authmethod);
}

static void add_merge(struct branch *branch, const char *name)
{
	ALLOC_GROW(branch->merge_name, branch->merge_nr + 1,
		   branch->merge_alloc);
	branch->merge_name[branch->merge_nr++] = name;
}

struct branches_hash_key {
	const char *str;
	int len;
};

static int branches_hash_cmp(const void *cmp_data UNUSED,
			     const struct hashmap_entry *eptr,
			     const struct hashmap_entry *entry_or_key,
			     const void *keydata)
{
	const struct branch *a, *b;
	const struct branches_hash_key *key = keydata;

	a = container_of(eptr, const struct branch, ent);
	b = container_of(entry_or_key, const struct branch, ent);

	if (key)
		return strncmp(a->name, key->str, key->len) ||
		       a->name[key->len];
	else
		return strcmp(a->name, b->name);
}

static struct branch *find_branch(struct remote_state *remote_state,
				  const char *name, size_t len)
{
	struct branches_hash_key lookup;
	struct hashmap_entry lookup_entry, *e;

	lookup.str = name;
	lookup.len = len;
	hashmap_entry_init(&lookup_entry, memhash(name, len));

	e = hashmap_get(&remote_state->branches_hash, &lookup_entry, &lookup);
	if (e)
		return container_of(e, struct branch, ent);

	return NULL;
}

static void die_on_missing_branch(struct repository *repo,
				  struct branch *branch)
{
	/* branch == NULL is always valid because it represents detached HEAD. */
	if (branch &&
	    branch != find_branch(repo->remote_state, branch->name,
				  strlen(branch->name)))
		die("branch %s was not found in the repository", branch->name);
}

static struct branch *make_branch(struct remote_state *remote_state,
				  const char *name, size_t len)
{
	struct branch *ret;

	ret = find_branch(remote_state, name, len);
	if (ret)
		return ret;

	CALLOC_ARRAY(ret, 1);
	ret->name = xstrndup(name, len);
	ret->refname = xstrfmt("refs/heads/%s", ret->name);

	hashmap_entry_init(&ret->ent, memhash(name, len));
	if (hashmap_put_entry(&remote_state->branches_hash, ret, ent))
		BUG("hashmap_put overwrote entry after hashmap_get returned NULL");
	return ret;
}

static struct rewrite *make_rewrite(struct rewrites *r,
				    const char *base, size_t len)
{
	struct rewrite *ret;
	int i;

	for (i = 0; i < r->rewrite_nr; i++) {
		if (len == r->rewrite[i]->baselen &&
		    !strncmp(base, r->rewrite[i]->base, len))
			return r->rewrite[i];
	}

	ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
	CALLOC_ARRAY(ret, 1);
	r->rewrite[r->rewrite_nr++] = ret;
	ret->base = xstrndup(base, len);
	ret->baselen = len;
	return ret;
}

static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
{
	ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
	rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
	rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
	rewrite->instead_of_nr++;
}

static const char *skip_spaces(const char *s)
{
	while (isspace(*s))
		s++;
	return s;
}

static void read_remotes_file(struct remote_state *remote_state,
			      struct remote *remote)
{
	struct strbuf buf = STRBUF_INIT;
	FILE *f = fopen_or_warn(git_path("remotes/%s", remote->name), "r");

	if (!f)
		return;
	remote->configured_in_repo = 1;
	remote->origin = REMOTE_REMOTES;
	while (strbuf_getline(&buf, f) != EOF) {
		const char *v;

		strbuf_rtrim(&buf);

		if (skip_prefix(buf.buf, "URL:", &v))
			add_url_alias(remote_state, remote,
				      xstrdup(skip_spaces(v)));
		else if (skip_prefix(buf.buf, "Push:", &v))
			refspec_append(&remote->push, skip_spaces(v));
		else if (skip_prefix(buf.buf, "Pull:", &v))
			refspec_append(&remote->fetch, skip_spaces(v));
	}
	strbuf_release(&buf);
	fclose(f);
}

static void read_branches_file(struct remote_state *remote_state,
			       struct remote *remote)
{
	char *frag;
	struct strbuf buf = STRBUF_INIT;
	FILE *f = fopen_or_warn(git_path("branches/%s", remote->name), "r");

	if (!f)
		return;

	strbuf_getline_lf(&buf, f);
	fclose(f);
	strbuf_trim(&buf);
	if (!buf.len) {
		strbuf_release(&buf);
		return;
	}

	remote->configured_in_repo = 1;
	remote->origin = REMOTE_BRANCHES;

	/*
	 * The branches file would have URL and optionally
	 * #branch specified.  The default (or specified) branch is
	 * fetched and stored in the local branch matching the
	 * remote name.
	 */
	frag = strchr(buf.buf, '#');
	if (frag)
		*(frag++) = '\0';
	else
		frag = (char *)git_default_branch_name(0);

	add_url_alias(remote_state, remote, strbuf_detach(&buf, NULL));
	refspec_appendf(&remote->fetch, "refs/heads/%s:refs/heads/%s",
			frag, remote->name);

	/*
	 * Cogito compatible push: push current HEAD to remote #branch
	 * (master if missing)
	 */
	refspec_appendf(&remote->push, "HEAD:refs/heads/%s", frag);
	remote->fetch_tags = 1; /* always auto-follow */
}

static int handle_config(const char *key, const char *value,
			 const struct config_context *ctx, void *cb)
{
	const char *name;
	size_t namelen;
	const char *subkey;
	struct remote *remote;
	struct branch *branch;
	struct remote_state *remote_state = cb;
	const struct key_value_info *kvi = ctx->kvi;

	if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
		/* There is no subsection. */
		if (!name)
			return 0;
		/* There is a subsection, but it is empty. */
		if (!namelen)
			return -1;
		branch = make_branch(remote_state, name, namelen);
		if (!strcmp(subkey, "remote")) {
			return git_config_string(&branch->remote_name, key, value);
		} else if (!strcmp(subkey, "pushremote")) {
			return git_config_string(&branch->pushremote_name, key, value);
		} else if (!strcmp(subkey, "merge")) {
			if (!value)
				return config_error_nonbool(key);
			add_merge(branch, xstrdup(value));
		}
		return 0;
	}
	if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
		struct rewrite *rewrite;
		if (!name)
			return 0;
		if (!strcmp(subkey, "insteadof")) {
			if (!value)
				return config_error_nonbool(key);
			rewrite = make_rewrite(&remote_state->rewrites, name,
					       namelen);
			add_instead_of(rewrite, xstrdup(value));
		} else if (!strcmp(subkey, "pushinsteadof")) {
			if (!value)
				return config_error_nonbool(key);
			rewrite = make_rewrite(&remote_state->rewrites_push,
					       name, namelen);
			add_instead_of(rewrite, xstrdup(value));
		}
	}

	if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
		return 0;

	/* Handle remote.* variables */
	if (!name && !strcmp(subkey, "pushdefault"))
		return git_config_string(&remote_state->pushremote_name, key,
					 value);

	if (!name)
		return 0;
	/* Handle remote.<name>.* variables */
	if (*name == '/') {
		warning(_("config remote shorthand cannot begin with '/': %s"),
			name);
		return 0;
	}
	remote = make_remote(remote_state, name, namelen);
	remote->origin = REMOTE_CONFIG;
	if (kvi->scope == CONFIG_SCOPE_LOCAL ||
	    kvi->scope == CONFIG_SCOPE_WORKTREE)
		remote->configured_in_repo = 1;
	if (!strcmp(subkey, "mirror"))
		remote->mirror = git_config_bool(key, value);
	else if (!strcmp(subkey, "skipdefaultupdate"))
		remote->skip_default_update = git_config_bool(key, value);
	else if (!strcmp(subkey, "skipfetchall"))
		remote->skip_default_update = git_config_bool(key, value);
	else if (!strcmp(subkey, "prune"))
		remote->prune = git_config_bool(key, value);
	else if (!strcmp(subkey, "prunetags"))
		remote->prune_tags = git_config_bool(key, value);
	else if (!strcmp(subkey, "url")) {
		const char *v;
		if (git_config_string(&v, key, value))
			return -1;
		add_url(remote, v);
	} else if (!strcmp(subkey, "pushurl")) {
		const char *v;
		if (git_config_string(&v, key, value))
			return -1;
		add_pushurl(remote, v);
	} else if (!strcmp(subkey, "push")) {
		const char *v;
		if (git_config_string(&v, key, value))
			return -1;
		refspec_append(&remote->push, v);
		free((char *)v);
	} else if (!strcmp(subkey, "fetch")) {
		const char *v;
		if (git_config_string(&v, key, value))
			return -1;
		refspec_append(&remote->fetch, v);
		free((char *)v);
	} else if (!strcmp(subkey, "receivepack")) {
		const char *v;
		if (git_config_string(&v, key, value))
			return -1;
		if (!remote->receivepack)
			remote->receivepack = v;
		else
			error(_("more than one receivepack given, using the first"));
	} else if (!strcmp(subkey, "uploadpack")) {
		const char *v;
		if (git_config_string(&v, key, value))
			return -1;
		if (!remote->uploadpack)
			remote->uploadpack = v;
		else
			error(_("more than one uploadpack given, using the first"));
	} else if (!strcmp(subkey, "tagopt")) {
		if (!strcmp(value, "--no-tags"))
			remote->fetch_tags = -1;
		else if (!strcmp(value, "--tags"))
			remote->fetch_tags = 2;
	} else if (!strcmp(subkey, "proxy")) {
		return git_config_string((const char **)&remote->http_proxy,
					 key, value);
	} else if (!strcmp(subkey, "proxyauthmethod")) {
		return git_config_string((const char **)&remote->http_proxy_authmethod,
					 key, value);
	} else if (!strcmp(subkey, "vcs")) {
		return git_config_string(&remote->foreign_vcs, key, value);
	}
	return 0;
}

static void alias_all_urls(struct remote_state *remote_state)
{
	int i, j;
	for (i = 0; i < remote_state->remotes_nr; i++) {
		int add_pushurl_aliases;
		if (!remote_state->remotes[i])
			continue;
		for (j = 0; j < remote_state->remotes[i]->pushurl_nr; j++) {
			remote_state->remotes[i]->pushurl[j] =
				alias_url(remote_state->remotes[i]->pushurl[j],
					  &remote_state->rewrites);
		}
		add_pushurl_aliases = remote_state->remotes[i]->pushurl_nr == 0;
		for (j = 0; j < remote_state->remotes[i]->url_nr; j++) {
			if (add_pushurl_aliases)
				add_pushurl_alias(
					remote_state, remote_state->remotes[i],
					remote_state->remotes[i]->url[j]);
			remote_state->remotes[i]->url[j] =
				alias_url(remote_state->remotes[i]->url[j],
					  &remote_state->rewrites);
		}
	}
}

static void read_config(struct repository *repo)
{
	int flag;

	if (repo->remote_state->initialized)
		return;
	repo->remote_state->initialized = 1;

	repo->remote_state->current_branch = NULL;
	if (startup_info->have_repository) {
		const char *head_ref = refs_resolve_ref_unsafe(
			get_main_ref_store(repo), "HEAD", 0, NULL, &flag);
		if (head_ref && (flag & REF_ISSYMREF) &&
		    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
			repo->remote_state->current_branch = make_branch(
				repo->remote_state, head_ref, strlen(head_ref));
		}
	}
	repo_config(repo, handle_config, repo->remote_state);
	alias_all_urls(repo->remote_state);
}

static int valid_remote_nick(const char *name)
{
	if (!name[0] || is_dot_or_dotdot(name))
		return 0;

	/* remote nicknames cannot contain slashes */
	while (*name)
		if (is_dir_sep(*name++))
			return 0;
	return 1;
}

static const char *remotes_remote_for_branch(struct remote_state *remote_state,
					     struct branch *branch,
					     int *explicit)
{
	if (branch && branch->remote_name) {
		if (explicit)
			*explicit = 1;
		return branch->remote_name;
	}
	if (explicit)
		*explicit = 0;
	if (remote_state->remotes_nr == 1)
		return remote_state->remotes[0]->name;
	return "origin";
}

const char *remote_for_branch(struct branch *branch, int *explicit)
{
	read_config(the_repository);
	die_on_missing_branch(the_repository, branch);

	return remotes_remote_for_branch(the_repository->remote_state, branch,
					 explicit);
}

static const char *
remotes_pushremote_for_branch(struct remote_state *remote_state,
			      struct branch *branch, int *explicit)
{
	if (branch && branch->pushremote_name) {
		if (explicit)
			*explicit = 1;
		return branch->pushremote_name;
	}
	if (remote_state->pushremote_name) {
		if (explicit)
			*explicit = 1;
		return remote_state->pushremote_name;
	}
	return remotes_remote_for_branch(remote_state, branch, explicit);
}

const char *pushremote_for_branch(struct branch *branch, int *explicit)
{
	read_config(the_repository);
	die_on_missing_branch(the_repository, branch);

	return remotes_pushremote_for_branch(the_repository->remote_state,
					     branch, explicit);
}

static struct remote *remotes_remote_get(struct remote_state *remote_state,
					 const char *name);

const char *remote_ref_for_branch(struct branch *branch, int for_push)
{
	read_config(the_repository);
	die_on_missing_branch(the_repository, branch);

	if (branch) {
		if (!for_push) {
			if (branch->merge_nr) {
				return branch->merge_name[0];
			}
		} else {
			const char *dst,
				*remote_name = remotes_pushremote_for_branch(
					the_repository->remote_state, branch,
					NULL);
			struct remote *remote = remotes_remote_get(
				the_repository->remote_state, remote_name);

			if (remote && remote->push.nr &&
			    (dst = apply_refspecs(&remote->push,
						  branch->refname))) {
				return dst;
			}
		}
	}
	return NULL;
}

static void validate_remote_url(struct remote *remote)
{
	int i;
	const char *value;
	struct strbuf redacted = STRBUF_INIT;
	int warn_not_die;

	if (git_config_get_string_tmp("transfer.credentialsinurl", &value))
		return;

	if (!strcmp("warn", value))
		warn_not_die = 1;
	else if (!strcmp("die", value))
		warn_not_die = 0;
	else if (!strcmp("allow", value))
		return;
	else
		die(_("unrecognized value transfer.credentialsInUrl: '%s'"), value);

	for (i = 0; i < remote->url_nr; i++) {
		struct url_info url_info = { 0 };

		if (!url_normalize(remote->url[i], &url_info) ||
		    !url_info.passwd_off)
			goto loop_cleanup;

		strbuf_reset(&redacted);
		strbuf_add(&redacted, url_info.url, url_info.passwd_off);
		strbuf_addstr(&redacted, "<redacted>");
		strbuf_addstr(&redacted,
			      url_info.url + url_info.passwd_off + url_info.passwd_len);

		if (warn_not_die)
			warning(_("URL '%s' uses plaintext credentials"), redacted.buf);
		else
			die(_("URL '%s' uses plaintext credentials"), redacted.buf);

loop_cleanup:
		free(url_info.url);
	}

	strbuf_release(&redacted);
}

static struct remote *
remotes_remote_get_1(struct remote_state *remote_state, const char *name,
		     const char *(*get_default)(struct remote_state *,
						struct branch *, int *))
{
	struct remote *ret;
	int name_given = 0;

	if (name)
		name_given = 1;
	else
		name = get_default(remote_state, remote_state->current_branch,
				   &name_given);

	ret = make_remote(remote_state, name, 0);
	if (valid_remote_nick(name) && have_git_dir()) {
		if (!valid_remote(ret))
			read_remotes_file(remote_state, ret);
		if (!valid_remote(ret))
			read_branches_file(remote_state, ret);
	}
	if (name_given && !valid_remote(ret))
		add_url_alias(remote_state, ret, name);
	if (!valid_remote(ret))
		return NULL;

	validate_remote_url(ret);

	return ret;
}

static inline struct remote *
remotes_remote_get(struct remote_state *remote_state, const char *name)
{
	return remotes_remote_get_1(remote_state, name,
				    remotes_remote_for_branch);
}

struct remote *remote_get(const char *name)
{
	read_config(the_repository);
	return remotes_remote_get(the_repository->remote_state, name);
}

static inline struct remote *
remotes_pushremote_get(struct remote_state *remote_state, const char *name)
{
	return remotes_remote_get_1(remote_state, name,
				    remotes_pushremote_for_branch);
}

struct remote *pushremote_get(const char *name)
{
	read_config(the_repository);
	return remotes_pushremote_get(the_repository->remote_state, name);
}

int remote_is_configured(struct remote *remote, int in_repo)
{
	if (!remote)
		return 0;
	if (in_repo)
		return remote->configured_in_repo;
	return !!remote->origin;
}

int for_each_remote(each_remote_fn fn, void *priv)
{
	int i, result = 0;
	read_config(the_repository);
	for (i = 0; i < the_repository->remote_state->remotes_nr && !result;
	     i++) {
		struct remote *remote =
			the_repository->remote_state->remotes[i];
		if (!remote)
			continue;
		result = fn(remote, priv);
	}
	return result;
}

static void handle_duplicate(struct ref *ref1, struct ref *ref2)
{
	if (strcmp(ref1->name, ref2->name)) {
		if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
		    ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
			die(_("Cannot fetch both %s and %s to %s"),
			    ref1->name, ref2->name, ref2->peer_ref->name);
		} else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
			   ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
			warning(_("%s usually tracks %s, not %s"),
				ref2->peer_ref->name, ref2->name, ref1->name);
		} else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
			   ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
			die(_("%s tracks both %s and %s"),
			    ref2->peer_ref->name, ref1->name, ref2->name);
		} else {
			/*
			 * This last possibility doesn't occur because
			 * FETCH_HEAD_IGNORE entries always appear at
			 * the end of the list.
			 */
			BUG("Internal error");
		}
	}
	free(ref2->peer_ref);
	free(ref2);
}

struct ref *ref_remove_duplicates(struct ref *ref_map)
{
	struct string_list refs = STRING_LIST_INIT_NODUP;
	struct ref *retval = NULL;
	struct ref **p = &retval;

	while (ref_map) {
		struct ref *ref = ref_map;

		ref_map = ref_map->next;
		ref->next = NULL;

		if (!ref->peer_ref) {
			*p = ref;
			p = &ref->next;
		} else {
			struct string_list_item *item =
				string_list_insert(&refs, ref->peer_ref->name);

			if (item->util) {
				/* Entry already existed */
				handle_duplicate((struct ref *)item->util, ref);
			} else {
				*p = ref;
				p = &ref->next;
				item->util = ref;
			}
		}
	}

	string_list_clear(&refs, 0);
	return retval;
}

int remote_has_url(struct remote *remote, const char *url)
{
	int i;
	for (i = 0; i < remote->url_nr; i++) {
		if (!strcmp(remote->url[i], url))
			return 1;
	}
	return 0;
}

static int match_name_with_pattern(const char *key, const char *name,
				   const char *value, char **result)
{
	const char *kstar = strchr(key, '*');
	size_t klen;
	size_t ksuffixlen;
	size_t namelen;
	int ret;
	if (!kstar)
		die(_("key '%s' of pattern had no '*'"), key);
	klen = kstar - key;
	ksuffixlen = strlen(kstar + 1);
	namelen = strlen(name);
	ret = !strncmp(name, key, klen) && namelen >= klen + ksuffixlen &&
		!memcmp(name + namelen - ksuffixlen, kstar + 1, ksuffixlen);
	if (ret && value) {
		struct strbuf sb = STRBUF_INIT;
		const char *vstar = strchr(value, '*');
		if (!vstar)
			die(_("value '%s' of pattern has no '*'"), value);
		strbuf_add(&sb, value, vstar - value);
		strbuf_add(&sb, name + klen, namelen - klen - ksuffixlen);
		strbuf_addstr(&sb, vstar + 1);
		*result = strbuf_detach(&sb, NULL);
	}
	return ret;
}

static int refspec_match(const struct refspec_item *refspec,
			 const char *name)
{
	if (refspec->pattern)
		return match_name_with_pattern(refspec->src, name, NULL, NULL);

	return !strcmp(refspec->src, name);
}

int omit_name_by_refspec(const char *name, struct refspec *rs)
{
	int i;

	for (i = 0; i < rs->nr; i++) {
		if (rs->items[i].negative && refspec_match(&rs->items[i], name))
			return 1;
	}
	return 0;
}

struct ref *apply_negative_refspecs(struct ref *ref_map, struct refspec *rs)
{
	struct ref **tail;

	for (tail = &ref_map; *tail; ) {
		struct ref *ref = *tail;

		if (omit_name_by_refspec(ref->name, rs)) {
			*tail = ref->next;
			free(ref->peer_ref);
			free(ref);
		} else
			tail = &ref->next;
	}

	return ref_map;
}

static int query_matches_negative_refspec(struct refspec *rs, struct refspec_item *query)
{
	int i, matched_negative = 0;
	int find_src = !query->src;
	struct string_list reversed = STRING_LIST_INIT_DUP;
	const char *needle = find_src ? query->dst : query->src;

	/*
	 * Check whether the queried ref matches any negative refpsec. If so,
	 * then we should ultimately treat this as not matching the query at
	 * all.
	 *
	 * Note that negative refspecs always match the source, but the query
	 * item uses the destination. To handle this, we apply pattern
	 * refspecs in reverse to figure out if the query source matches any
	 * of the negative refspecs.
	 *
	 * The first loop finds and expands all positive refspecs
	 * matched by the queried ref.
	 *
	 * The second loop checks if any of the results of the first loop
	 * match any negative refspec.
	 */
	for (i = 0; i < rs->nr; i++) {
		struct refspec_item *refspec = &rs->items[i];
		char *expn_name;

		if (refspec->negative)
			continue;

		/* Note the reversal of src and dst */
		if (refspec->pattern) {
			const char *key = refspec->dst ? refspec->dst : refspec->src;
			const char *value = refspec->src;

			if (match_name_with_pattern(key, needle, value, &expn_name))
				string_list_append_nodup(&reversed, expn_name);
		} else if (refspec->matching) {
			/* For the special matching refspec, any query should match */
			string_list_append(&reversed, needle);
		} else if (!refspec->src) {
			BUG("refspec->src should not be null here");
		} else if (!strcmp(needle, refspec->src)) {
			string_list_append(&reversed, refspec->src);
		}
	}

	for (i = 0; !matched_negative && i < reversed.nr; i++) {
		if (omit_name_by_refspec(reversed.items[i].string, rs))
			matched_negative = 1;
	}

	string_list_clear(&reversed, 0);

	return matched_negative;
}

static void query_refspecs_multiple(struct refspec *rs,
				    struct refspec_item *query,
				    struct string_list *results)
{
	int i;
	int find_src = !query->src;

	if (find_src && !query->dst)
		BUG("query_refspecs_multiple: need either src or dst");

	if (query_matches_negative_refspec(rs, query))
		return;

	for (i = 0; i < rs->nr; i++) {
		struct refspec_item *refspec = &rs->items[i];
		const char *key = find_src ? refspec->dst : refspec->src;
		const char *value = find_src ? refspec->src : refspec->dst;
		const char *needle = find_src ? query->dst : query->src;
		char **result = find_src ? &query->src : &query->dst;

		if (!refspec->dst || refspec->negative)
			continue;
		if (refspec->pattern) {
			if (match_name_with_pattern(key, needle, value, result))
				string_list_append_nodup(results, *result);
		} else if (!strcmp(needle, key)) {
			string_list_append(results, value);
		}
	}
}

int query_refspecs(struct refspec *rs, struct refspec_item *query)
{
	int i;
	int find_src = !query->src;
	const char *needle = find_src ? query->dst : query->src;
	char **result = find_src ? &query->src : &query->dst;

	if (find_src && !query->dst)
		BUG("query_refspecs: need either src or dst");

	if (query_matches_negative_refspec(rs, query))
		return -1;

	for (i = 0; i < rs->nr; i++) {
		struct refspec_item *refspec = &rs->items[i];
		const char *key = find_src ? refspec->dst : refspec->src;
		const char *value = find_src ? refspec->src : refspec->dst;

		if (!refspec->dst || refspec->negative)
			continue;
		if (refspec->pattern) {
			if (match_name_with_pattern(key, needle, value, result)) {
				query->force = refspec->force;
				return 0;
			}
		} else if (!strcmp(needle, key)) {
			*result = xstrdup(value);
			query->force = refspec->force;
			return 0;
		}
	}
	return -1;
}

char *apply_refspecs(struct refspec *rs, const char *name)
{
	struct refspec_item query;

	memset(&query, 0, sizeof(struct refspec_item));
	query.src = (char *)name;

	if (query_refspecs(rs, &query))
		return NULL;

	return query.dst;
}

int remote_find_tracking(struct remote *remote, struct refspec_item *refspec)
{
	return query_refspecs(&remote->fetch, refspec);
}

static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
		const char *name)
{
	size_t len = strlen(name);
	struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
	memcpy(ref->name, prefix, prefixlen);
	memcpy(ref->name + prefixlen, name, len);
	return ref;
}

struct ref *alloc_ref(const char *name)
{
	return alloc_ref_with_prefix("", 0, name);
}

struct ref *copy_ref(const struct ref *ref)
{
	struct ref *cpy;
	size_t len;
	if (!ref)
		return NULL;
	len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
	cpy = xmalloc(len);
	memcpy(cpy, ref, len);
	cpy->next = NULL;
	cpy->symref = xstrdup_or_null(ref->symref);
	cpy->remote_status = xstrdup_or_null(ref->remote_status);
	cpy->peer_ref = copy_ref(ref->peer_ref);
	return cpy;
}

struct ref *copy_ref_list(const struct ref *ref)
{
	struct ref *ret = NULL;
	struct ref **tail = &ret;
	while (ref) {
		*tail = copy_ref(ref);
		ref = ref->next;
		tail = &((*tail)->next);
	}
	return ret;
}

void free_one_ref(struct ref *ref)
{
	if (!ref)
		return;
	free_one_ref(ref->peer_ref);
	free(ref->remote_status);
	free(ref->symref);
	free(ref);
}

void free_refs(struct ref *ref)
{
	struct ref *next;
	while (ref) {
		next = ref->next;
		free_one_ref(ref);
		ref = next;
	}
}

int count_refspec_match(const char *pattern,
			struct ref *refs,
			struct ref **matched_ref)
{
	int patlen = strlen(pattern);
	struct ref *matched_weak = NULL;
	struct ref *matched = NULL;
	int weak_match = 0;
	int match = 0;

	for (weak_match = match = 0; refs; refs = refs->next) {
		char *name = refs->name;
		int namelen = strlen(name);

		if (!refname_match(pattern, name))
			continue;

		/* A match is "weak" if it is with refs outside
		 * heads or tags, and did not specify the pattern
		 * in full (e.g. "refs/remotes/origin/master") or at
		 * least from the toplevel (e.g. "remotes/origin/master");
		 * otherwise "git push $URL master" would result in
		 * ambiguity between remotes/origin/master and heads/master
		 * at the remote site.
		 */
		if (namelen != patlen &&
		    patlen != namelen - 5 &&
		    !starts_with(name, "refs/heads/") &&
		    !starts_with(name, "refs/tags/")) {
			/* We want to catch the case where only weak
			 * matches are found and there are multiple
			 * matches, and where more than one strong
			 * matches are found, as ambiguous.  One
			 * strong match with zero or more weak matches
			 * are acceptable as a unique match.
			 */
			matched_weak = refs;
			weak_match++;
		}
		else {
			matched = refs;
			match++;
		}
	}
	if (!matched) {
		if (matched_ref)
			*matched_ref = matched_weak;
		return weak_match;
	}
	else {
		if (matched_ref)
			*matched_ref = matched;
		return match;
	}
}

static void tail_link_ref(struct ref *ref, struct ref ***tail)
{
	**tail = ref;
	while (ref->next)
		ref = ref->next;
	*tail = &ref->next;
}

static struct ref *alloc_delete_ref(void)
{
	struct ref *ref = alloc_ref("(delete)");
	oidclr(&ref->new_oid);
	return ref;
}

static int try_explicit_object_name(const char *name,
				    struct ref **match)
{
	struct object_id oid;

	if (!*name) {
		if (match)
			*match = alloc_delete_ref();
		return 0;
	}

	if (repo_get_oid(the_repository, name, &oid))
		return -1;

	if (match) {
		*match = alloc_ref(name);
		oidcpy(&(*match)->new_oid, &oid);
	}
	return 0;
}

static struct ref *make_linked_ref(const char *name, struct ref ***tail)
{
	struct ref *ret = alloc_ref(name);
	tail_link_ref(ret, tail);
	return ret;
}

static char *guess_ref(const char *name, struct ref *peer)
{
	struct strbuf buf = STRBUF_INIT;

	const char *r = resolve_ref_unsafe(peer->name, RESOLVE_REF_READING,
					   NULL, NULL);
	if (!r)
		return NULL;

	if (starts_with(r, "refs/heads/")) {
		strbuf_addstr(&buf, "refs/heads/");
	} else if (starts_with(r, "refs/tags/")) {
		strbuf_addstr(&buf, "refs/tags/");
	} else {
		return NULL;
	}

	strbuf_addstr(&buf, name);
	return strbuf_detach(&buf, NULL);
}

static int match_explicit_lhs(struct ref *src,
			      struct refspec_item *rs,
			      struct ref **match,
			      int *allocated_match)
{
	switch (count_refspec_match(rs->src, src, match)) {
	case 1:
		if (allocated_match)
			*allocated_match = 0;
		return 0;
	case 0:
		/* The source could be in the get_sha1() format
		 * not a reference name.  :refs/other is a
		 * way to delete 'other' ref at the remote end.
		 */
		if (try_explicit_object_name(rs->src, match) < 0)
			return error(_("src refspec %s does not match any"), rs->src);
		if (allocated_match)
			*allocated_match = 1;
		return 0;
	default:
		return error(_("src refspec %s matches more than one"), rs->src);
	}
}

static void show_push_unqualified_ref_name_error(const char *dst_value,
						 const char *matched_src_name)
{
	struct object_id oid;
	enum object_type type;

	/*
	 * TRANSLATORS: "matches '%s'%" is the <dst> part of "git push
	 * <remote> <src>:<dst>" push, and "being pushed ('%s')" is
	 * the <src>.
	 */
	error(_("The destination you provided is not a full refname (i.e.,\n"
		"starting with \"refs/\"). We tried to guess what you meant by:\n"
		"\n"
		"- Looking for a ref that matches '%s' on the remote side.\n"
		"- Checking if the <src> being pushed ('%s')\n"
		"  is a ref in \"refs/{heads,tags}/\". If so we add a corresponding\n"
		"  refs/{heads,tags}/ prefix on the remote side.\n"
		"\n"
		"Neither worked, so we gave up. You must fully qualify the ref."),
	      dst_value, matched_src_name);

	if (!advice_enabled(ADVICE_PUSH_UNQUALIFIED_REF_NAME))
		return;

	if (repo_get_oid(the_repository, matched_src_name, &oid))
		BUG("'%s' is not a valid object, "
		    "match_explicit_lhs() should catch this!",
		    matched_src_name);
	type = oid_object_info(the_repository, &oid, NULL);
	if (type == OBJ_COMMIT) {
		advise(_("The <src> part of the refspec is a commit object.\n"
			 "Did you mean to create a new branch by pushing to\n"
			 "'%s:refs/heads/%s'?"),
		       matched_src_name, dst_value);
	} else if (type == OBJ_TAG) {
		advise(_("The <src> part of the refspec is a tag object.\n"
			 "Did you mean to create a new tag by pushing to\n"
			 "'%s:refs/tags/%s'?"),
		       matched_src_name, dst_value);
	} else if (type == OBJ_TREE) {
		advise(_("The <src> part of the refspec is a tree object.\n"
			 "Did you mean to tag a new tree by pushing to\n"
			 "'%s:refs/tags/%s'?"),
		       matched_src_name, dst_value);
	} else if (type == OBJ_BLOB) {
		advise(_("The <src> part of the refspec is a blob object.\n"
			 "Did you mean to tag a new blob by pushing to\n"
			 "'%s:refs/tags/%s'?"),
		       matched_src_name, dst_value);
	} else {
		BUG("'%s' should be commit/tag/tree/blob, is '%d'",
		    matched_src_name, type);
	}
}

static int match_explicit(struct ref *src, struct ref *dst,
			  struct ref ***dst_tail,
			  struct refspec_item *rs)
{
	struct ref *matched_src, *matched_dst;
	int allocated_src;

	const char *dst_value = rs->dst;
	char *dst_guess;

	if (rs->pattern || rs->matching || rs->negative)
		return 0;

	matched_src = matched_dst = NULL;
	if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0)
		return -1;

	if (!dst_value) {
		int flag;

		dst_value = resolve_ref_unsafe(matched_src->name,
					       RESOLVE_REF_READING,
					       NULL, &flag);
		if (!dst_value ||
		    ((flag & REF_ISSYMREF) &&
		     !starts_with(dst_value, "refs/heads/")))
			die(_("%s cannot be resolved to branch"),
			    matched_src->name);
	}

	switch (count_refspec_match(dst_value, dst, &matched_dst)) {
	case 1:
		break;
	case 0:
		if (starts_with(dst_value, "refs/")) {
			matched_dst = make_linked_ref(dst_value, dst_tail);
		} else if (is_null_oid(&matched_src->new_oid)) {
			error(_("unable to delete '%s': remote ref does not exist"),
			      dst_value);
		} else if ((dst_guess = guess_ref(dst_value, matched_src))) {
			matched_dst = make_linked_ref(dst_guess, dst_tail);
			free(dst_guess);
		} else {
			show_push_unqualified_ref_name_error(dst_value,
							     matched_src->name);
		}
		break;
	default:
		matched_dst = NULL;
		error(_("dst refspec %s matches more than one"),
		      dst_value);
		break;
	}
	if (!matched_dst)
		return -1;
	if (matched_dst->peer_ref)
		return error(_("dst ref %s receives from more than one src"),
			     matched_dst->name);
	else {
		matched_dst->peer_ref = allocated_src ?
					matched_src :
					copy_ref(matched_src);
		matched_dst->force = rs->force;
	}
	return 0;
}

static int match_explicit_refs(struct ref *src, struct ref *dst,
			       struct ref ***dst_tail, struct refspec *rs)
{
	int i, errs;
	for (i = errs = 0; i < rs->nr; i++)
		errs += match_explicit(src, dst, dst_tail, &rs->items[i]);
	return errs;
}

static char *get_ref_match(const struct refspec *rs, const struct ref *ref,
			   int send_mirror, int direction,
			   const struct refspec_item **ret_pat)
{
	const struct refspec_item *pat;
	char *name;
	int i;
	int matching_refs = -1;
	for (i = 0; i < rs->nr; i++) {
		const struct refspec_item *item = &rs->items[i];

		if (item->negative)
			continue;

		if (item->matching &&
		    (matching_refs == -1 || item->force)) {
			matching_refs = i;
			continue;
		}

		if (item->pattern) {
			const char *dst_side = item->dst ? item->dst : item->src;
			int match;
			if (direction == FROM_SRC)
				match = match_name_with_pattern(item->src, ref->name, dst_side, &name);
			else
				match = match_name_with_pattern(dst_side, ref->name, item->src, &name);
			if (match) {
				matching_refs = i;
				break;
			}
		}
	}
	if (matching_refs == -1)
		return NULL;

	pat = &rs->items[matching_refs];
	if (pat->matching) {
		/*
		 * "matching refs"; traditionally we pushed everything
		 * including refs outside refs/heads/ hierarchy, but
		 * that does not make much sense these days.
		 */
		if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
			return NULL;
		name = xstrdup(ref->name);
	}
	if (ret_pat)
		*ret_pat = pat;
	return name;
}

static struct ref **tail_ref(struct ref **head)
{
	struct ref **tail = head;
	while (*tail)
		tail = &((*tail)->next);
	return tail;
}

struct tips {
	struct commit **tip;
	int nr, alloc;
};

static void add_to_tips(struct tips *tips, const struct object_id *oid)
{
	struct commit *commit;

	if (is_null_oid(oid))
		return;
	commit = lookup_commit_reference_gently(the_repository, oid, 1);
	if (!commit || (commit->object.flags & TMP_MARK))
		return;
	commit->object.flags |= TMP_MARK;
	ALLOC_GROW(tips->tip, tips->nr + 1, tips->alloc);
	tips->tip[tips->nr++] = commit;
}

static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
{
	struct string_list dst_tag = STRING_LIST_INIT_NODUP;
	struct string_list src_tag = STRING_LIST_INIT_NODUP;
	struct string_list_item *item;
	struct ref *ref;
	struct tips sent_tips;

	/*
	 * Collect everything we know they would have at the end of
	 * this push, and collect all tags they have.
	 */
	memset(&sent_tips, 0, sizeof(sent_tips));
	for (ref = *dst; ref; ref = ref->next) {
		if (ref->peer_ref &&
		    !is_null_oid(&ref->peer_ref->new_oid))
			add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
		else
			add_to_tips(&sent_tips, &ref->old_oid);
		if (starts_with(ref->name, "refs/tags/"))
			string_list_append(&dst_tag, ref->name);
	}
	clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);

	string_list_sort(&dst_tag);

	/* Collect tags they do not have. */
	for (ref = src; ref; ref = ref->next) {
		if (!starts_with(ref->name, "refs/tags/"))
			continue; /* not a tag */
		if (string_list_has_string(&dst_tag, ref->name))
			continue; /* they already have it */
		if (oid_object_info(the_repository, &ref->new_oid, NULL) != OBJ_TAG)
			continue; /* be conservative */
		item = string_list_append(&src_tag, ref->name);
		item->util = ref;
	}
	string_list_clear(&dst_tag, 0);

	/*
	 * At this point, src_tag lists tags that are missing from
	 * dst, and sent_tips lists the tips we are pushing or those
	 * that we know they already have. An element in the src_tag
	 * that is an ancestor of any of the sent_tips needs to be
	 * sent to the other side.
	 */
	if (sent_tips.nr) {
		const int reachable_flag = 1;
		struct commit_list *found_commits;
		struct commit **src_commits;
		int nr_src_commits = 0, alloc_src_commits = 16;
		ALLOC_ARRAY(src_commits, alloc_src_commits);

		for_each_string_list_item(item, &src_tag) {
			struct ref *ref = item->util;
			struct commit *commit;

			if (is_null_oid(&ref->new_oid))
				continue;
			commit = lookup_commit_reference_gently(the_repository,
								&ref->new_oid,
								1);
			if (!commit)
				/* not pushing a commit, which is not an error */
				continue;

			ALLOC_GROW(src_commits, nr_src_commits + 1, alloc_src_commits);
			src_commits[nr_src_commits++] = commit;
		}

		found_commits = get_reachable_subset(sent_tips.tip, sent_tips.nr,
						     src_commits, nr_src_commits,
						     reachable_flag);

		for_each_string_list_item(item, &src_tag) {
			struct ref *dst_ref;
			struct ref *ref = item->util;
			struct commit *commit;

			if (is_null_oid(&ref->new_oid))
				continue;
			commit = lookup_commit_reference_gently(the_repository,
								&ref->new_oid,
								1);
			if (!commit)
				/* not pushing a commit, which is not an error */
				continue;

			/*
			 * Is this tag, which they do not have, reachable from
			 * any of the commits we are sending?
			 */
			if (!(commit->object.flags & reachable_flag))
				continue;

			/* Add it in */
			dst_ref = make_linked_ref(ref->name, dst_tail);
			oidcpy(&dst_ref->new_oid, &ref->new_oid);
			dst_ref->peer_ref = copy_ref(ref);
		}

		clear_commit_marks_many(nr_src_commits, src_commits, reachable_flag);
		free(src_commits);
		free_commit_list(found_commits);
	}

	string_list_clear(&src_tag, 0);
	free(sent_tips.tip);
}

struct ref *find_ref_by_name(const struct ref *list, const char *name)
{
	for ( ; list; list = list->next)
		if (!strcmp(list->name, name))
			return (struct ref *)list;
	return NULL;
}

static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
{
	for ( ; ref; ref = ref->next)
		string_list_append_nodup(ref_index, ref->name)->util = ref;

	string_list_sort(ref_index);
}

/*
 * Given only the set of local refs, sanity-check the set of push
 * refspecs. We can't catch all errors that match_push_refs would,
 * but we can catch some errors early before even talking to the
 * remote side.
 */
int check_push_refs(struct ref *src, struct refspec *rs)
{
	int ret = 0;
	int i;

	for (i = 0; i < rs->nr; i++) {
		struct refspec_item *item = &rs->items[i];

		if (item->pattern || item->matching || item->negative)
			continue;

		ret |= match_explicit_lhs(src, item, NULL, NULL);
	}

	return ret;
}

/*
 * Given the set of refs the local repository has, the set of refs the
 * remote repository has, and the refspec used for push, determine
 * what remote refs we will update and with what value by setting
 * peer_ref (which object is being pushed) and force (if the push is
 * forced) in elements of "dst". The function may add new elements to
 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
 */
int match_push_refs(struct ref *src, struct ref **dst,
		    struct refspec *rs, int flags)
{
	int send_all = flags & MATCH_REFS_ALL;
	int send_mirror = flags & MATCH_REFS_MIRROR;
	int send_prune = flags & MATCH_REFS_PRUNE;
	int errs;
	struct ref *ref, **dst_tail = tail_ref(dst);
	struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;

	/* If no refspec is provided, use the default ":" */
	if (!rs->nr)
		refspec_append(rs, ":");

	errs = match_explicit_refs(src, *dst, &dst_tail, rs);

	/* pick the remainder */
	for (ref = src; ref; ref = ref->next) {
		struct string_list_item *dst_item;
		struct ref *dst_peer;
		const struct refspec_item *pat = NULL;
		char *dst_name;

		dst_name = get_ref_match(rs, ref, send_mirror, FROM_SRC, &pat);
		if (!dst_name)
			continue;

		if (!dst_ref_index.nr)
			prepare_ref_index(&dst_ref_index, *dst);

		dst_item = string_list_lookup(&dst_ref_index, dst_name);
		dst_peer = dst_item ? dst_item->util : NULL;
		if (dst_peer) {
			if (dst_peer->peer_ref)
				/* We're already sending something to this ref. */
				goto free_name;
		} else {
			if (pat->matching && !(send_all || send_mirror))
				/*
				 * Remote doesn't have it, and we have no
				 * explicit pattern, and we don't have
				 * --all or --mirror.
				 */
				goto free_name;

			/* Create a new one and link it */
			dst_peer = make_linked_ref(dst_name, &dst_tail);
			oidcpy(&dst_peer->new_oid, &ref->new_oid);
			string_list_insert(&dst_ref_index,
				dst_peer->name)->util = dst_peer;
		}
		dst_peer->peer_ref = copy_ref(ref);
		dst_peer->force = pat->force;
	free_name:
		free(dst_name);
	}

	string_list_clear(&dst_ref_index, 0);

	if (flags & MATCH_REFS_FOLLOW_TAGS)
		add_missing_tags(src, dst, &dst_tail);

	if (send_prune) {
		struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
		/* check for missing refs on the remote */
		for (ref = *dst; ref; ref = ref->next) {
			char *src_name;

			if (ref->peer_ref)
				/* We're already sending something to this ref. */
				continue;

			src_name = get_ref_match(rs, ref, send_mirror, FROM_DST, NULL);
			if (src_name) {
				if (!src_ref_index.nr)
					prepare_ref_index(&src_ref_index, src);
				if (!string_list_has_string(&src_ref_index,
					    src_name))
					ref->peer_ref = alloc_delete_ref();
				free(src_name);
			}
		}
		string_list_clear(&src_ref_index, 0);
	}

	*dst = apply_negative_refspecs(*dst, rs);

	if (errs)
		return -1;
	return 0;
}

void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
			     int force_update)
{
	struct ref *ref;

	for (ref = remote_refs; ref; ref = ref->next) {
		int force_ref_update = ref->force || force_update;
		int reject_reason = 0;

		if (ref->peer_ref)
			oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
		else if (!send_mirror)
			continue;

		ref->deletion = is_null_oid(&ref->new_oid);
		if (!ref->deletion &&
			oideq(&ref->old_oid, &ref->new_oid)) {
			ref->status = REF_STATUS_UPTODATE;
			continue;
		}

		/*
		 * If the remote ref has moved and is now different
		 * from what we expect, reject any push.
		 *
		 * It also is an error if the user told us to check
		 * with the remote-tracking branch to find the value
		 * to expect, but we did not have such a tracking
		 * branch.
		 *
		 * If the tip of the remote-tracking ref is unreachable
		 * from any reflog entry of its local ref indicating a
		 * possible update since checkout; reject the push.
		 */
		if (ref->expect_old_sha1) {
			if (!oideq(&ref->old_oid, &ref->old_oid_expect))
				reject_reason = REF_STATUS_REJECT_STALE;
			else if (ref->check_reachable && ref->unreachable)
				reject_reason =
					REF_STATUS_REJECT_REMOTE_UPDATED;
			else
				/*
				 * If the ref isn't stale, and is reachable
				 * from one of the reflog entries of
				 * the local branch, force the update.
				 */
				force_ref_update = 1;
		}

		/*
		 * If the update isn't already rejected then check
		 * the usual "must fast-forward" rules.
		 *
		 * Decide whether an individual refspec A:B can be
		 * pushed.  The push will succeed if any of the
		 * following are true:
		 *
		 * (1) the remote reference B does not exist
		 *
		 * (2) the remote reference B is being removed (i.e.,
		 *     pushing :B where no source is specified)
		 *
		 * (3) the destination is not under refs/tags/, and
		 *     if the old and new value is a commit, the new
		 *     is a descendant of the old.
		 *
		 * (4) it is forced using the +A:B notation, or by
		 *     passing the --force argument
		 */

		if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
			if (starts_with(ref->name, "refs/tags/"))
				reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
			else if (!repo_has_object_file(the_repository, &ref->old_oid))
				reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
			else if (!lookup_commit_reference_gently(the_repository, &ref->old_oid, 1) ||
				 !lookup_commit_reference_gently(the_repository, &ref->new_oid, 1))
				reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
			else if (!ref_newer(&ref->new_oid, &ref->old_oid))
				reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
		}

		/*
		 * "--force" will defeat any rejection implemented
		 * by the rules above.
		 */
		if (!force_ref_update)
			ref->status = reject_reason;
		else if (reject_reason)
			ref->forced_update = 1;
	}
}

static void set_merge(struct remote_state *remote_state, struct branch *ret)
{
	struct remote *remote;
	char *ref;
	struct object_id oid;
	int i;

	if (!ret)
		return; /* no branch */
	if (ret->merge)
		return; /* already run */
	if (!ret->remote_name || !ret->merge_nr) {
		/*
		 * no merge config; let's make sure we don't confuse callers
		 * with a non-zero merge_nr but a NULL merge
		 */
		ret->merge_nr = 0;
		return;
	}

	remote = remotes_remote_get(remote_state, ret->remote_name);

	CALLOC_ARRAY(ret->merge, ret->merge_nr);
	for (i = 0; i < ret->merge_nr; i++) {
		ret->merge[i] = xcalloc(1, sizeof(**ret->merge));
		ret->merge[i]->src = xstrdup(ret->merge_name[i]);
		if (!remote_find_tracking(remote, ret->merge[i]) ||
		    strcmp(ret->remote_name, "."))
			continue;
		if (repo_dwim_ref(the_repository, ret->merge_name[i],
				  strlen(ret->merge_name[i]), &oid, &ref,
				  0) == 1)
			ret->merge[i]->dst = ref;
		else
			ret->merge[i]->dst = xstrdup(ret->merge_name[i]);
	}
}

struct branch *branch_get(const char *name)
{
	struct branch *ret;

	read_config(the_repository);
	if (!name || !*name || !strcmp(name, "HEAD"))
		ret = the_repository->remote_state->current_branch;
	else
		ret = make_branch(the_repository->remote_state, name,
				  strlen(name));
	set_merge(the_repository->remote_state, ret);
	return ret;
}

int branch_has_merge_config(struct branch *branch)
{
	return branch && !!branch->merge;
}

int branch_merge_matches(struct branch *branch,
		                 int i,
		                 const char *refname)
{
	if (!branch || i < 0 || i >= branch->merge_nr)
		return 0;
	return refname_match(branch->merge[i]->src, refname);
}

__attribute__((format (printf,2,3)))
static const char *error_buf(struct strbuf *err, const char *fmt, ...)
{
	if (err) {
		va_list ap;
		va_start(ap, fmt);
		strbuf_vaddf(err, fmt, ap);
		va_end(ap);
	}
	return NULL;
}

const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
{
	if (!branch)
		return error_buf(err, _("HEAD does not point to a branch"));

	if (!branch->merge || !branch->merge[0]) {
		/*
		 * no merge config; is it because the user didn't define any,
		 * or because it is not a real branch, and get_branch
		 * auto-vivified it?
		 */
		if (!ref_exists(branch->refname))
			return error_buf(err, _("no such branch: '%s'"),
					 branch->name);
		return error_buf(err,
				 _("no upstream configured for branch '%s'"),
				 branch->name);
	}

	if (!branch->merge[0]->dst)
		return error_buf(err,
				 _("upstream branch '%s' not stored as a remote-tracking branch"),
				 branch->merge[0]->src);

	return branch->merge[0]->dst;
}

static const char *tracking_for_push_dest(struct remote *remote,
					  const char *refname,
					  struct strbuf *err)
{
	char *ret;

	ret = apply_refspecs(&remote->fetch, refname);
	if (!ret)
		return error_buf(err,
				 _("push destination '%s' on remote '%s' has no local tracking branch"),
				 refname, remote->name);
	return ret;
}

static const char *branch_get_push_1(struct remote_state *remote_state,
				     struct branch *branch, struct strbuf *err)
{
	struct remote *remote;

	remote = remotes_remote_get(
		remote_state,
		remotes_pushremote_for_branch(remote_state, branch, NULL));
	if (!remote)
		return error_buf(err,
				 _("branch '%s' has no remote for pushing"),
				 branch->name);

	if (remote->push.nr) {
		char *dst;
		const char *ret;

		dst = apply_refspecs(&remote->push, branch->refname);
		if (!dst)
			return error_buf(err,
					 _("push refspecs for '%s' do not include '%s'"),
					 remote->name, branch->name);

		ret = tracking_for_push_dest(remote, dst, err);
		free(dst);
		return ret;
	}

	if (remote->mirror)
		return tracking_for_push_dest(remote, branch->refname, err);

	switch (push_default) {
	case PUSH_DEFAULT_NOTHING:
		return error_buf(err, _("push has no destination (push.default is 'nothing')"));

	case PUSH_DEFAULT_MATCHING:
	case PUSH_DEFAULT_CURRENT:
		return tracking_for_push_dest(remote, branch->refname, err);

	case PUSH_DEFAULT_UPSTREAM:
		return branch_get_upstream(branch, err);

	case PUSH_DEFAULT_UNSPECIFIED:
	case PUSH_DEFAULT_SIMPLE:
		{
			const char *up, *cur;

			up = branch_get_upstream(branch, err);
			if (!up)
				return NULL;
			cur = tracking_for_push_dest(remote, branch->refname, err);
			if (!cur)
				return NULL;
			if (strcmp(cur, up))
				return error_buf(err,
						 _("cannot resolve 'simple' push to a single destination"));
			return cur;
		}
	}

	BUG("unhandled push situation");
}

const char *branch_get_push(struct branch *branch, struct strbuf *err)
{
	read_config(the_repository);
	die_on_missing_branch(the_repository, branch);

	if (!branch)
		return error_buf(err, _("HEAD does not point to a branch"));

	if (!branch->push_tracking_ref)
		branch->push_tracking_ref = branch_get_push_1(
			the_repository->remote_state, branch, err);
	return branch->push_tracking_ref;
}

static int ignore_symref_update(const char *refname, struct strbuf *scratch)
{
	return !refs_read_symbolic_ref(get_main_ref_store(the_repository), refname, scratch);
}

/*
 * Create and return a list of (struct ref) consisting of copies of
 * each remote_ref that matches refspec.  refspec must be a pattern.
 * Fill in the copies' peer_ref to describe the local tracking refs to
 * which they map.  Omit any references that would map to an existing
 * local symbolic ref.
 */
static struct ref *get_expanded_map(const struct ref *remote_refs,
				    const struct refspec_item *refspec)
{
	struct strbuf scratch = STRBUF_INIT;
	const struct ref *ref;
	struct ref *ret = NULL;
	struct ref **tail = &ret;

	for (ref = remote_refs; ref; ref = ref->next) {
		char *expn_name = NULL;

		strbuf_reset(&scratch);

		if (strchr(ref->name, '^'))
			continue; /* a dereference item */
		if (match_name_with_pattern(refspec->src, ref->name,
					    refspec->dst, &expn_name) &&
		    !ignore_symref_update(expn_name, &scratch)) {
			struct ref *cpy = copy_ref(ref);

			cpy->peer_ref = alloc_ref(expn_name);
			if (refspec->force)
				cpy->peer_ref->force = 1;
			*tail = cpy;
			tail = &cpy->next;
		}
		free(expn_name);
	}

	strbuf_release(&scratch);
	return ret;
}

static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
{
	const struct ref *ref;
	const struct ref *best_match = NULL;
	int best_score = 0;

	for (ref = refs; ref; ref = ref->next) {
		int score = refname_match(name, ref->name);

		if (best_score < score) {
			best_match = ref;
			best_score = score;
		}
	}
	return best_match;
}

struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
{
	const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);

	if (!ref)
		return NULL;

	return copy_ref(ref);
}

static struct ref *get_local_ref(const char *name)
{
	if (!name || name[0] == '\0')
		return NULL;

	if (starts_with(name, "refs/"))
		return alloc_ref(name);

	if (starts_with(name, "heads/") ||
	    starts_with(name, "tags/") ||
	    starts_with(name, "remotes/"))
		return alloc_ref_with_prefix("refs/", 5, name);

	return alloc_ref_with_prefix("refs/heads/", 11, name);
}

int get_fetch_map(const struct ref *remote_refs,
		  const struct refspec_item *refspec,
		  struct ref ***tail,
		  int missing_ok)
{
	struct ref *ref_map, **rmp;

	if (refspec->negative)
		return 0;

	if (refspec->pattern) {
		ref_map = get_expanded_map(remote_refs, refspec);
	} else {
		const char *name = refspec->src[0] ? refspec->src : "HEAD";

		if (refspec->exact_sha1) {
			ref_map = alloc_ref(name);
			get_oid_hex(name, &ref_map->old_oid);
			ref_map->exact_oid = 1;
		} else {
			ref_map = get_remote_ref(remote_refs, name);
		}
		if (!missing_ok && !ref_map)
			die(_("couldn't find remote ref %s"), name);
		if (ref_map) {
			ref_map->peer_ref = get_local_ref(refspec->dst);
			if (ref_map->peer_ref && refspec->force)
				ref_map->peer_ref->force = 1;
		}
	}

	for (rmp = &ref_map; *rmp; ) {
		if ((*rmp)->peer_ref) {
			if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
			    check_refname_format((*rmp)->peer_ref->name, 0)) {
				struct ref *ignore = *rmp;
				error(_("* Ignoring funny ref '%s' locally"),
				      (*rmp)->peer_ref->name);
				*rmp = (*rmp)->next;
				free(ignore->peer_ref);
				free(ignore);
				continue;
			}
		}
		rmp = &((*rmp)->next);
	}

	if (ref_map)
		tail_link_ref(ref_map, tail);

	return 0;
}

int resolve_remote_symref(struct ref *ref, struct ref *list)
{
	if (!ref->symref)
		return 0;
	for (; list; list = list->next)
		if (!strcmp(ref->symref, list->name)) {
			oidcpy(&ref->old_oid, &list->old_oid);
			return 0;
		}
	return 1;
}

/*
 * Compute the commit ahead/behind values for the pair branch_name, base.
 *
 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
 * set to zero).
 *
 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., ref
 * does not exist).  Returns 0 if the commits are identical.  Returns 1 if
 * commits are different.
 */

static int stat_branch_pair(const char *branch_name, const char *base,
			     int *num_ours, int *num_theirs,
			     enum ahead_behind_flags abf)
{
	struct object_id oid;
	struct commit *ours, *theirs;
	struct rev_info revs;
	struct setup_revision_opt opt = {
		.free_removed_argv_elements = 1,
	};
	struct strvec argv = STRVEC_INIT;

	/* Cannot stat if what we used to build on no longer exists */
	if (read_ref(base, &oid))
		return -1;
	theirs = lookup_commit_reference(the_repository, &oid);
	if (!theirs)
		return -1;

	if (read_ref(branch_name, &oid))
		return -1;
	ours = lookup_commit_reference(the_repository, &oid);
	if (!ours)
		return -1;

	*num_theirs = *num_ours = 0;

	/* are we the same? */
	if (theirs == ours)
		return 0;
	if (abf == AHEAD_BEHIND_QUICK)
		return 1;
	if (abf != AHEAD_BEHIND_FULL)
		BUG("stat_branch_pair: invalid abf '%d'", abf);

	/* Run "rev-list --left-right ours...theirs" internally... */
	strvec_push(&argv, ""); /* ignored */
	strvec_push(&argv, "--left-right");
	strvec_pushf(&argv, "%s...%s",
		     oid_to_hex(&ours->object.oid),
		     oid_to_hex(&theirs->object.oid));
	strvec_push(&argv, "--");

	repo_init_revisions(the_repository, &revs, NULL);
	setup_revisions(argv.nr, argv.v, &revs, &opt);
	if (prepare_revision_walk(&revs))
		die(_("revision walk setup failed"));

	/* ... and count the commits on each side. */
	while (1) {
		struct commit *c = get_revision(&revs);
		if (!c)
			break;
		if (c->object.flags & SYMMETRIC_LEFT)
			(*num_ours)++;
		else
			(*num_theirs)++;
	}

	/* clear object flags smudged by the above traversal */
	clear_commit_marks(ours, ALL_REV_FLAGS);
	clear_commit_marks(theirs, ALL_REV_FLAGS);

	strvec_clear(&argv);
	release_revisions(&revs);
	return 1;
}

/*
 * Lookup the tracking branch for the given branch and if present, optionally
 * compute the commit ahead/behind values for the pair.
 *
 * If for_push is true, the tracking branch refers to the push branch,
 * otherwise it refers to the upstream branch.
 *
 * The name of the tracking branch (or NULL if it is not defined) is
 * returned via *tracking_name, if it is not itself NULL.
 *
 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
 * set to zero).
 *
 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
 * upstream defined, or ref does not exist).  Returns 0 if the commits are
 * identical.  Returns 1 if commits are different.
 */
int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
		       const char **tracking_name, int for_push,
		       enum ahead_behind_flags abf)
{
	const char *base;

	/* Cannot stat unless we are marked to build on top of somebody else. */
	base = for_push ? branch_get_push(branch, NULL) :
		branch_get_upstream(branch, NULL);
	if (tracking_name)
		*tracking_name = base;
	if (!base)
		return -1;

	return stat_branch_pair(branch->refname, base, num_ours, num_theirs, abf);
}

/*
 * Return true when there is anything to report, otherwise false.
 */
int format_tracking_info(struct branch *branch, struct strbuf *sb,
			 enum ahead_behind_flags abf,
			 int show_divergence_advice)
{
	int ours, theirs, sti;
	const char *full_base;
	char *base;
	int upstream_is_gone = 0;

	sti = stat_tracking_info(branch, &ours, &theirs, &full_base, 0, abf);
	if (sti < 0) {
		if (!full_base)
			return 0;
		upstream_is_gone = 1;
	}

	base = shorten_unambiguous_ref(full_base, 0);
	if (upstream_is_gone) {
		strbuf_addf(sb,
			_("Your branch is based on '%s', but the upstream is gone.\n"),
			base);
		if (advice_enabled(ADVICE_STATUS_HINTS))
			strbuf_addstr(sb,
				_("  (use \"git branch --unset-upstream\" to fixup)\n"));
	} else if (!sti) {
		strbuf_addf(sb,
			_("Your branch is up to date with '%s'.\n"),
			base);
	} else if (abf == AHEAD_BEHIND_QUICK) {
		strbuf_addf(sb,
			    _("Your branch and '%s' refer to different commits.\n"),
			    base);
		if (advice_enabled(ADVICE_STATUS_HINTS))
			strbuf_addf(sb, _("  (use \"%s\" for details)\n"),
				    "git status --ahead-behind");
	} else if (!theirs) {
		strbuf_addf(sb,
			Q_("Your branch is ahead of '%s' by %d commit.\n",
			   "Your branch is ahead of '%s' by %d commits.\n",
			   ours),
			base, ours);
		if (advice_enabled(ADVICE_STATUS_HINTS))
			strbuf_addstr(sb,
				_("  (use \"git push\" to publish your local commits)\n"));
	} else if (!ours) {
		strbuf_addf(sb,
			Q_("Your branch is behind '%s' by %d commit, "
			       "and can be fast-forwarded.\n",
			   "Your branch is behind '%s' by %d commits, "
			       "and can be fast-forwarded.\n",
			   theirs),
			base, theirs);
		if (advice_enabled(ADVICE_STATUS_HINTS))
			strbuf_addstr(sb,
				_("  (use \"git pull\" to update your local branch)\n"));
	} else {
		strbuf_addf(sb,
			Q_("Your branch and '%s' have diverged,\n"
			       "and have %d and %d different commit each, "
			       "respectively.\n",
			   "Your branch and '%s' have diverged,\n"
			       "and have %d and %d different commits each, "
			       "respectively.\n",
			   ours + theirs),
			base, ours, theirs);
		if (show_divergence_advice &&
		    advice_enabled(ADVICE_STATUS_HINTS))
			strbuf_addstr(sb,
				_("  (use \"git pull\" if you want to integrate the remote branch with yours)\n"));
	}
	free(base);
	return 1;
}

static int one_local_ref(const char *refname, const struct object_id *oid,
			 int flag UNUSED,
			 void *cb_data)
{
	struct ref ***local_tail = cb_data;
	struct ref *ref;

	/* we already know it starts with refs/ to get here */
	if (check_refname_format(refname + 5, 0))
		return 0;

	ref = alloc_ref(refname);
	oidcpy(&ref->new_oid, oid);
	**local_tail = ref;
	*local_tail = &ref->next;
	return 0;
}

struct ref *get_local_heads(void)
{
	struct ref *local_refs = NULL, **local_tail = &local_refs;

	for_each_ref(one_local_ref, &local_tail);
	return local_refs;
}

struct ref *guess_remote_head(const struct ref *head,
			      const struct ref *refs,
			      int all)
{
	const struct ref *r;
	struct ref *list = NULL;
	struct ref **tail = &list;

	if (!head)
		return NULL;

	/*
	 * Some transports support directly peeking at
	 * where HEAD points; if that is the case, then
	 * we don't have to guess.
	 */
	if (head->symref)
		return copy_ref(find_ref_by_name(refs, head->symref));

	/* If a remote branch exists with the default branch name, let's use it. */
	if (!all) {
		char *ref = xstrfmt("refs/heads/%s",
				    git_default_branch_name(0));

		r = find_ref_by_name(refs, ref);
		free(ref);
		if (r && oideq(&r->old_oid, &head->old_oid))
			return copy_ref(r);

		/* Fall back to the hard-coded historical default */
		r = find_ref_by_name(refs, "refs/heads/master");
		if (r && oideq(&r->old_oid, &head->old_oid))
			return copy_ref(r);
	}

	/* Look for another ref that points there */
	for (r = refs; r; r = r->next) {
		if (r != head &&
		    starts_with(r->name, "refs/heads/") &&
		    oideq(&r->old_oid, &head->old_oid)) {
			*tail = copy_ref(r);
			tail = &((*tail)->next);
			if (!all)
				break;
		}
	}

	return list;
}

struct stale_heads_info {
	struct string_list *ref_names;
	struct ref **stale_refs_tail;
	struct refspec *rs;
};

static int get_stale_heads_cb(const char *refname, const struct object_id *oid,
			      int flags, void *cb_data)
{
	struct stale_heads_info *info = cb_data;
	struct string_list matches = STRING_LIST_INIT_DUP;
	struct refspec_item query;
	int i, stale = 1;
	memset(&query, 0, sizeof(struct refspec_item));
	query.dst = (char *)refname;

	query_refspecs_multiple(info->rs, &query, &matches);
	if (matches.nr == 0)
		goto clean_exit; /* No matches */

	/*
	 * If we did find a suitable refspec and it's not a symref and
	 * it's not in the list of refs that currently exist in that
	 * remote, we consider it to be stale. In order to deal with
	 * overlapping refspecs, we need to go over all of the
	 * matching refs.
	 */
	if (flags & REF_ISSYMREF)
		goto clean_exit;

	for (i = 0; stale && i < matches.nr; i++)
		if (string_list_has_string(info->ref_names, matches.items[i].string))
			stale = 0;

	if (stale) {
		struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
		oidcpy(&ref->new_oid, oid);
	}

clean_exit:
	string_list_clear(&matches, 0);
	return 0;
}

struct ref *get_stale_heads(struct refspec *rs, struct ref *fetch_map)
{
	struct ref *ref, *stale_refs = NULL;
	struct string_list ref_names = STRING_LIST_INIT_NODUP;
	struct stale_heads_info info;

	info.ref_names = &ref_names;
	info.stale_refs_tail = &stale_refs;
	info.rs = rs;
	for (ref = fetch_map; ref; ref = ref->next)
		string_list_append(&ref_names, ref->name);
	string_list_sort(&ref_names);
	for_each_ref(get_stale_heads_cb, &info);
	string_list_clear(&ref_names, 0);
	return stale_refs;
}

/*
 * Compare-and-swap
 */
static void clear_cas_option(struct push_cas_option *cas)
{
	int i;

	for (i = 0; i < cas->nr; i++)
		free(cas->entry[i].refname);
	free(cas->entry);
	memset(cas, 0, sizeof(*cas));
}

static struct push_cas *add_cas_entry(struct push_cas_option *cas,
				      const char *refname,
				      size_t refnamelen)
{
	struct push_cas *entry;
	ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
	entry = &cas->entry[cas->nr++];
	memset(entry, 0, sizeof(*entry));
	entry->refname = xmemdupz(refname, refnamelen);
	return entry;
}

static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
{
	const char *colon;
	struct push_cas *entry;

	if (unset) {
		/* "--no-<option>" */
		clear_cas_option(cas);
		return 0;
	}

	if (!arg) {
		/* just "--<option>" */
		cas->use_tracking_for_rest = 1;
		return 0;
	}

	/* "--<option>=refname" or "--<option>=refname:value" */
	colon = strchrnul(arg, ':');
	entry = add_cas_entry(cas, arg, colon - arg);
	if (!*colon)
		entry->use_tracking = 1;
	else if (!colon[1])
		oidclr(&entry->expect);
	else if (repo_get_oid(the_repository, colon + 1, &entry->expect))
		return error(_("cannot parse expected object name '%s'"),
			     colon + 1);
	return 0;
}

int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
{
	return parse_push_cas_option(opt->value, arg, unset);
}

int is_empty_cas(const struct push_cas_option *cas)
{
	return !cas->use_tracking_for_rest && !cas->nr;
}

/*
 * Look at remote.fetch refspec and see if we have a remote
 * tracking branch for the refname there. Fill the name of
 * the remote-tracking branch in *dst_refname, and the name
 * of the commit object at its tip in oid[].
 * If we cannot do so, return negative to signal an error.
 */
static int remote_tracking(struct remote *remote, const char *refname,
			   struct object_id *oid, char **dst_refname)
{
	char *dst;

	dst = apply_refspecs(&remote->fetch, refname);
	if (!dst)
		return -1; /* no tracking ref for refname at remote */
	if (read_ref(dst, oid))
		return -1; /* we know what the tracking ref is but we cannot read it */

	*dst_refname = dst;
	return 0;
}

/*
 * The struct "reflog_commit_array" and related helper functions
 * are used for collecting commits into an array during reflog
 * traversals in "check_and_collect_until()".
 */
struct reflog_commit_array {
	struct commit **item;
	size_t nr, alloc;
};

#define REFLOG_COMMIT_ARRAY_INIT { 0 }

/* Append a commit to the array. */
static void append_commit(struct reflog_commit_array *arr,
			  struct commit *commit)
{
	ALLOC_GROW(arr->item, arr->nr + 1, arr->alloc);
	arr->item[arr->nr++] = commit;
}

/* Free and reset the array. */
static void free_commit_array(struct reflog_commit_array *arr)
{
	FREE_AND_NULL(arr->item);
	arr->nr = arr->alloc = 0;
}

struct check_and_collect_until_cb_data {
	struct commit *remote_commit;
	struct reflog_commit_array *local_commits;
	timestamp_t remote_reflog_timestamp;
};

/* Get the timestamp of the latest entry. */
static int peek_reflog(struct object_id *o_oid UNUSED,
		       struct object_id *n_oid UNUSED,
		       const char *ident UNUSED,
		       timestamp_t timestamp, int tz UNUSED,
		       const char *message UNUSED, void *cb_data)
{
	timestamp_t *ts = cb_data;
	*ts = timestamp;
	return 1;
}

static int check_and_collect_until(struct object_id *o_oid UNUSED,
				   struct object_id *n_oid,
				   const char *ident UNUSED,
				   timestamp_t timestamp, int tz UNUSED,
				   const char *message UNUSED, void *cb_data)
{
	struct commit *commit;
	struct check_and_collect_until_cb_data *cb = cb_data;

	/* An entry was found. */
	if (oideq(n_oid, &cb->remote_commit->object.oid))
		return 1;

	if ((commit = lookup_commit_reference(the_repository, n_oid)))
		append_commit(cb->local_commits, commit);

	/*
	 * If the reflog entry timestamp is older than the remote ref's
	 * latest reflog entry, there is no need to check or collect
	 * entries older than this one.
	 */
	if (timestamp < cb->remote_reflog_timestamp)
		return -1;

	return 0;
}

#define MERGE_BASES_BATCH_SIZE 8

/*
 * Iterate through the reflog of the local ref to check if there is an entry
 * for the given remote-tracking ref; runs until the timestamp of an entry is
 * older than latest timestamp of remote-tracking ref's reflog. Any commits
 * are that seen along the way are collected into an array to check if the
 * remote-tracking ref is reachable from any of them.
 */
static int is_reachable_in_reflog(const char *local, const struct ref *remote)
{
	timestamp_t date;
	struct commit *commit;
	struct commit **chunk;
	struct check_and_collect_until_cb_data cb;
	struct reflog_commit_array arr = REFLOG_COMMIT_ARRAY_INIT;
	size_t size = 0;
	int ret = 0;

	commit = lookup_commit_reference(the_repository, &remote->old_oid);
	if (!commit)
		goto cleanup_return;

	/*
	 * Get the timestamp from the latest entry
	 * of the remote-tracking ref's reflog.
	 */
	for_each_reflog_ent_reverse(remote->tracking_ref, peek_reflog, &date);

	cb.remote_commit = commit;
	cb.local_commits = &arr;
	cb.remote_reflog_timestamp = date;
	ret = for_each_reflog_ent_reverse(local, check_and_collect_until, &cb);

	/* We found an entry in the reflog. */
	if (ret > 0)
		goto cleanup_return;

	/*
	 * Check if the remote commit is reachable from any
	 * of the commits in the collected array, in batches.
	 */
	for (chunk = arr.item; chunk < arr.item + arr.nr; chunk += size) {
		size = arr.item + arr.nr - chunk;
		if (MERGE_BASES_BATCH_SIZE < size)
			size = MERGE_BASES_BATCH_SIZE;

		if ((ret = repo_in_merge_bases_many(the_repository, commit, size, chunk)))
			break;
	}

cleanup_return:
	free_commit_array(&arr);
	return ret;
}

/*
 * Check for reachability of a remote-tracking
 * ref in the reflog entries of its local ref.
 */
static void check_if_includes_upstream(struct ref *remote)
{
	struct ref *local = get_local_ref(remote->name);
	if (!local)
		return;

	if (is_reachable_in_reflog(local->name, remote) <= 0)
		remote->unreachable = 1;
}

static void apply_cas(struct push_cas_option *cas,
		      struct remote *remote,
		      struct ref *ref)
{
	int i;

	/* Find an explicit --<option>=<name>[:<value>] entry */
	for (i = 0; i < cas->nr; i++) {
		struct push_cas *entry = &cas->entry[i];
		if (!refname_match(entry->refname, ref->name))
			continue;
		ref->expect_old_sha1 = 1;
		if (!entry->use_tracking)
			oidcpy(&ref->old_oid_expect, &entry->expect);
		else if (remote_tracking(remote, ref->name,
					 &ref->old_oid_expect,
					 &ref->tracking_ref))
			oidclr(&ref->old_oid_expect);
		else
			ref->check_reachable = cas->use_force_if_includes;
		return;
	}

	/* Are we using "--<option>" to cover all? */
	if (!cas->use_tracking_for_rest)
		return;

	ref->expect_old_sha1 = 1;
	if (remote_tracking(remote, ref->name,
			    &ref->old_oid_expect,
			    &ref->tracking_ref))
		oidclr(&ref->old_oid_expect);
	else
		ref->check_reachable = cas->use_force_if_includes;
}

void apply_push_cas(struct push_cas_option *cas,
		    struct remote *remote,
		    struct ref *remote_refs)
{
	struct ref *ref;
	for (ref = remote_refs; ref; ref = ref->next) {
		apply_cas(cas, remote, ref);

		/*
		 * If "compare-and-swap" is in "use_tracking[_for_rest]"
		 * mode, and if "--force-if-includes" was specified, run
		 * the check.
		 */
		if (ref->check_reachable)
			check_if_includes_upstream(ref);
	}
}

struct remote_state *remote_state_new(void)
{
	struct remote_state *r = xmalloc(sizeof(*r));

	memset(r, 0, sizeof(*r));

	hashmap_init(&r->remotes_hash, remotes_hash_cmp, NULL, 0);
	hashmap_init(&r->branches_hash, branches_hash_cmp, NULL, 0);
	return r;
}

void remote_state_clear(struct remote_state *remote_state)
{
	int i;

	for (i = 0; i < remote_state->remotes_nr; i++)
		remote_clear(remote_state->remotes[i]);
	FREE_AND_NULL(remote_state->remotes);
	remote_state->remotes_alloc = 0;
	remote_state->remotes_nr = 0;

	hashmap_clear_and_free(&remote_state->remotes_hash, struct remote, ent);
	hashmap_clear_and_free(&remote_state->branches_hash, struct remote, ent);
}

/*
 * Returns 1 if it was the last chop before ':'.
 */
static int chop_last_dir(char **remoteurl, int is_relative)
{
	char *rfind = find_last_dir_sep(*remoteurl);
	if (rfind) {
		*rfind = '\0';
		return 0;
	}

	rfind = strrchr(*remoteurl, ':');
	if (rfind) {
		*rfind = '\0';
		return 1;
	}

	if (is_relative || !strcmp(".", *remoteurl))
		die(_("cannot strip one component off url '%s'"),
			*remoteurl);

	free(*remoteurl);
	*remoteurl = xstrdup(".");
	return 0;
}

char *relative_url(const char *remote_url, const char *url,
		   const char *up_path)
{
	int is_relative = 0;
	int colonsep = 0;
	char *out;
	char *remoteurl;
	struct strbuf sb = STRBUF_INIT;
	size_t len;

	if (!url_is_local_not_ssh(url) || is_absolute_path(url))
		return xstrdup(url);

	len = strlen(remote_url);
	if (!len)
		BUG("invalid empty remote_url");

	remoteurl = xstrdup(remote_url);
	if (is_dir_sep(remoteurl[len-1]))
		remoteurl[len-1] = '\0';

	if (!url_is_local_not_ssh(remoteurl) || is_absolute_path(remoteurl))
		is_relative = 0;
	else {
		is_relative = 1;
		/*
		 * Prepend a './' to ensure all relative
		 * remoteurls start with './' or '../'
		 */
		if (!starts_with_dot_slash_native(remoteurl) &&
		    !starts_with_dot_dot_slash_native(remoteurl)) {
			strbuf_reset(&sb);
			strbuf_addf(&sb, "./%s", remoteurl);
			free(remoteurl);
			remoteurl = strbuf_detach(&sb, NULL);
		}
	}
	/*
	 * When the url starts with '../', remove that and the
	 * last directory in remoteurl.
	 */
	while (*url) {
		if (starts_with_dot_dot_slash_native(url)) {
			url += 3;
			colonsep |= chop_last_dir(&remoteurl, is_relative);
		} else if (starts_with_dot_slash_native(url))
			url += 2;
		else
			break;
	}
	strbuf_reset(&sb);
	strbuf_addf(&sb, "%s%s%s", remoteurl, colonsep ? ":" : "/", url);
	if (ends_with(url, "/"))
		strbuf_setlen(&sb, sb.len - 1);
	free(remoteurl);

	if (starts_with_dot_slash_native(sb.buf))
		out = xstrdup(sb.buf + 2);
	else
		out = xstrdup(sb.buf);

	if (!up_path || !is_relative) {
		strbuf_release(&sb);
		return out;
	}

	strbuf_reset(&sb);
	strbuf_addf(&sb, "%s%s", up_path, out);
	free(out);
	return strbuf_detach(&sb, NULL);
}