1 files changed, 120 insertions, 0 deletions
diff --git a/src/roff/groff/tests/substring_works.sh b/src/roff/groff/tests/substring_works.sh
new file mode 100755
index 0000000..a57d579
--- /dev/null
+++ b/src/roff/groff/tests/substring_works.sh
@@ -0,0 +1,120 @@
+#!/bin/sh
+#
+# Copyright (C) 2021 Free Software Foundation, Inc.
+#
+# This file is part of groff.
+#
+# groff is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# groff 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 General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+groff="${abs_top_builddir:-.}/test-groff"
+
+# This test is based on a contribution by Jim Avera; see
+# <https://savannah.gnu.org/bugs/?60802>.
+
+"$groff" -z -ww <<'EOF'
+.
+.nr debug 1
+.de debugmsg
+.  if \\n[debug] .tm \\$*
+..
+.de errormsg
+.  tm ERROR: \\$*
+.  nr nerrors (\\n[nerrors]+1)
+..
+.nr nerrors 0
+.
+.\" .substring xx n1 [n2]
+.\"    Replace contents of string named xx with the substring bounded by
+.\"    zero-based indices indices n1 and n2.  Negative indices count
+.\"    backwards from the end of the string.  If omitted, n2 is `-1`.
+.\"
+.\"    If n1 > n2, n1 and n2 are swapped.  If n1 equals or exceeds the
+.\"    string length, it is set to `-1`.
+.\"
+.\"  NOT YET IMPLEMENTED:
+.\"    If n1 > n2, or if n1 equals or exceeds the string length, then
+.\"    any contents of xx are replaced with the empty string.
+.\"
+.de jtest \" input_string n1 n2 expected_result
+.  if \\n[.$]<4 .ab jtest: expected at least 4 arguments, got \\n[.$]
+.  ds t*input "\\$1
+.  ds t*n1 \\$2
+.  ds t*n2 \\$3
+.  ds t*expected "\\$4
+.  shift 4
+.  ds t*comment "\\$*
+.
+.  ds t*str "\\*[t*input]
+.  ie '\\*[t*n2]'' .substring t*str \\*[t*n1]
+.  el              .substring t*str \\*[t*n1] \\*[t*n2]
+.  ie '\\*[t*str]'\\*[t*expected]' \{\
+.    debugmsg .substring '\\*[t*input]' \\*[t*n1] \\*[t*n2] -> \
+'\\*[t*str]' (OK) \\*[t*comment]
+.  \}
+.  el \{\
+.    errormsg .substring '\\*[t*input]' \\*[t*n1] \\*[t*n2] yielded \
+'\\*[t*str]', EXPECTED '\\*[t*expected]' \\*[t*comment]
+.  \}
+..
+.
+.debugmsg --- Pick a single character from non-empty ---
+.jtest "abc" 0 0 "a"
+.jtest "abc" 1 1 "b"
+.jtest "abc" 2 2 "c"
+.
+.debugmsg --- Pick multiple characters from non-empty ---
+.jtest "abcd" 0 1 "ab"
+.jtest "abcd" 1 1 "b"
+.jtest "abcd" 0 3 "abcd"
+.jtest "abcd" 0 -1 "abcd"
+.jtest "abcd" 0 "" "abcd"
+.jtest "abcd" 1 3 "bcd"
+.jtest "abcd" 2 3 "cd"
+.jtest "abcd" 3 3 "d"
+.
+.debugmsg --- Omit n2 with non-empty input and non-empty result ---
+.jtest "abc" 0 "" "abc"
+.jtest "abc" 1 "" "bc"
+.jtest "abc" 2 "" "c"
+.jtest "a"   0 "" "a"
+.
+.\"debugmsg --- Specify empty substring with n2==(n1-1) ---
+.\"jtest "abcd" 3 2 ""
+.\"jtest "abcd" 2 1 ""
+.\"jtest "abcd" 1 0 ""
+.debugmsg --- Pick multiple characters from non-empty using inverted \
+range ---
+.jtest "abcd" 3 2 "cd"
+.jtest "abcd" 2 1 "bc"
+.jtest "abcd" 1 0 "ab"
+.
+.\"debugmsg --- Specify empty substring with n1==length and n2 omitted ---
+.\"jtest "abcd" 4 "" ""
+.\"jtest "abc" 3 "" ""
+.\"jtest "ab" 2 "" ""
+.\"jtest "a" 1 "" ""
+.\"jtest "" 0 "" ""
+.debugmsg --- Pick single character using out-of-bounds start index \
+(unless string empty) ---
+.jtest "abcd" 4 "" "d"
+.jtest "abc" 3 "" "c"
+.jtest "ab" 2 "" "b"
+.jtest "a" 1 "" "a"
+.jtest "" 0 "" ""
+.jtest "" 0 -1 ""
+.jtest "" 0 -2 ""
+.
+.if \n[nerrors] .ab Aborting, got \n[nerrors] errors.
+EOF