Adding upstream version 9.1.upstream/9.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 186 insertions, 0 deletions

diff --git a/lib/filevercmp.c b/lib/filevercmp.c
new file mode 100644
index 0000000..d546e79
--- /dev/null
+++ b/lib/filevercmp.c
@@ -0,0 +1,186 @@
+/* Compare file names containing version numbers.
+
+   Copyright (C) 1995 Ian Jackson <iwj10@cus.cam.ac.uk>
+   Copyright (C) 2001 Anthony Towns <aj@azure.humbug.org.au>
+   Copyright (C) 2008-2022 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+#include "filevercmp.h"
+
+#include <stdbool.h>
+#include <c-ctype.h>
+#include <limits.h>
+#include <idx.h>
+#include <verify.h>
+
+/* Return the length of a prefix of S that corresponds to the suffix
+   defined by this extended regular expression in the C locale:
+     (\.[A-Za-z~][A-Za-z0-9~]*)*$
+   If *LEN is -1, S is a string; set *LEN to S's length.
+   Otherwise, *LEN should be nonnegative, S is a char array,
+   and *LEN does not change.  */
+static idx_t
+file_prefixlen (char const *s, ptrdiff_t *len)
+{
+  size_t n = *len;  /* SIZE_MAX if N == -1.  */
+
+  for (idx_t i = 0; ; i++)
+    {
+      idx_t prefixlen = i;
+      while (i + 1 < n && s[i] == '.' && (c_isalpha (s[i + 1])
+                                          || s[i + 1] == '~'))
+        for (i += 2; i < n && (c_isalnum (s[i]) || s[i] == '~'); i++)
+          continue;
+
+      if (*len < 0 ? !s[i] : i == n)
+        {
+          *len = i;
+          return prefixlen;
+        }
+    }
+}
+
+/* Return a version sort comparison value for S's byte at position POS.
+   S has length LEN.  If POS == LEN, sort before all non-'~' bytes.  */
+
+static int
+order (char const *s, idx_t pos, idx_t len)
+{
+  if (pos == len)
+    return -1;
+
+  unsigned char c = s[pos];
+  if (c_isdigit (c))
+    return 0;
+  else if (c_isalpha (c))
+    return c;
+  else if (c == '~')
+    return -2;
+  else
+    {
+      verify (UCHAR_MAX <= (INT_MAX - 1 - 2) / 2);
+      return c + UCHAR_MAX + 1;
+    }
+}
+
+/* slightly modified verrevcmp function from dpkg
+   S1, S2 - compared char array
+   S1_LEN, S2_LEN - length of arrays to be scanned
+
+   This implements the algorithm for comparison of version strings
+   specified by Debian and now widely adopted.  The detailed
+   specification can be found in the Debian Policy Manual in the
+   section on the 'Version' control field.  This version of the code
+   implements that from s5.6.12 of Debian Policy v3.8.0.1
+   https://www.debian.org/doc/debian-policy/ch-controlfields.html#s-f-Version */
+static int _GL_ATTRIBUTE_PURE
+verrevcmp (const char *s1, idx_t s1_len, const char *s2, idx_t s2_len)
+{
+  idx_t s1_pos = 0;
+  idx_t s2_pos = 0;
+  while (s1_pos < s1_len || s2_pos < s2_len)
+    {
+      int first_diff = 0;
+      while ((s1_pos < s1_len && !c_isdigit (s1[s1_pos]))
+             || (s2_pos < s2_len && !c_isdigit (s2[s2_pos])))
+        {
+          int s1_c = order (s1, s1_pos, s1_len);
+          int s2_c = order (s2, s2_pos, s2_len);
+          if (s1_c != s2_c)
+            return s1_c - s2_c;
+          s1_pos++;
+          s2_pos++;
+        }
+      while (s1_pos < s1_len && s1[s1_pos] == '0')
+        s1_pos++;
+      while (s2_pos < s2_len && s2[s2_pos] == '0')
+        s2_pos++;
+      while (s1_pos < s1_len && s2_pos < s2_len
+             && c_isdigit (s1[s1_pos]) && c_isdigit (s2[s2_pos]))
+        {
+          if (!first_diff)
+            first_diff = s1[s1_pos] - s2[s2_pos];
+          s1_pos++;
+          s2_pos++;
+        }
+      if (s1_pos < s1_len && c_isdigit (s1[s1_pos]))
+        return 1;
+      if (s2_pos < s2_len && c_isdigit (s2[s2_pos]))
+        return -1;
+      if (first_diff)
+        return first_diff;
+    }
+  return 0;
+}
+
+/* Compare version strings S1 and S2.
+   See filevercmp.h for function description.  */
+int
+filevercmp (const char *s1, const char *s2)
+{
+  return filenvercmp (s1, -1, s2, -1);
+}
+
+/* Compare versions A (of length ALEN) and B (of length BLEN).
+   See filevercmp.h for function description.  */
+int
+filenvercmp (char const *a, ptrdiff_t alen, char const *b, ptrdiff_t blen)
+{
+  /* Special case for empty versions.  */
+  bool aempty = alen < 0 ? !a[0] : !alen;
+  bool bempty = blen < 0 ? !b[0] : !blen;
+  if (aempty)
+    return -!bempty;
+  if (bempty)
+    return 1;
+
+  /* Special cases for leading ".": "." sorts first, then "..", then
+     other names with leading ".", then other names.  */
+  if (a[0] == '.')
+    {
+      if (b[0] != '.')
+        return -1;
+
+      bool adot = alen < 0 ? !a[1] : alen == 1;
+      bool bdot = blen < 0 ? !b[1] : blen == 1;
+      if (adot)
+        return -!bdot;
+      if (bdot)
+        return 1;
+
+      bool adotdot = a[1] == '.' && (alen < 0 ? !a[2] : alen == 2);
+      bool bdotdot = b[1] == '.' && (blen < 0 ? !b[2] : blen == 2);
+      if (adotdot)
+        return -!bdotdot;
+      if (bdotdot)
+        return 1;
+    }
+  else if (b[0] == '.')
+    return 1;
+
+  /* Cut file suffixes.  */
+  idx_t aprefixlen = file_prefixlen (a, &alen);
+  idx_t bprefixlen = file_prefixlen (b, &blen);
+
+  /* If both suffixes are empty, a second pass would return the same thing.  */
+  bool one_pass_only = aprefixlen == alen && bprefixlen == blen;
+
+  int result = verrevcmp (a, aprefixlen, b, bprefixlen);
+
+  /* Return the initial result if nonzero, or if no second pass is needed.
+     Otherwise, restore the suffixes and try again.  */
+  return result || one_pass_only ? result : verrevcmp (a, alen, b, blen);
+}