Merge branch 'rj/test-regex'

Git ships with a fall-back regexp implementation for platforms with
buggy regexp library; give people a tool to see if they should be
using it on their platform.

* rj/test-regex:
  test-regex: Add a test to check for a bug in the regex routines

.gitignore

@@ -189,6 +189,7 @@
 /test-mktemp
 /test-parse-options
 /test-path-utils
+/test-regex
 /test-revision-walking
 /test-run-command
 /test-sha1

Makefile

@@ -496,6 +496,7 @@ TEST_PROGRAMS_NEED_X += test-mergesort
 TEST_PROGRAMS_NEED_X += test-mktemp
 TEST_PROGRAMS_NEED_X += test-parse-options
 TEST_PROGRAMS_NEED_X += test-path-utils
+TEST_PROGRAMS_NEED_X += test-regex
 TEST_PROGRAMS_NEED_X += test-revision-walking
 TEST_PROGRAMS_NEED_X += test-run-command
 TEST_PROGRAMS_NEED_X += test-scrap-cache-tree

t/t0070-fundamental.sh

@@ -25,4 +25,9 @@ test_expect_success POSIXPERM 'mktemp to unwritable directory prints filename' '
 	grep "cannotwrite/test" err
 '
 
+test_expect_success 'check for a bug in the regex routines' '
+	# if this test fails, re-build git with NO_REGEX=1
+	test-regex
+'
+
 test_done

test-regex.c

@@ -0,0 +1,20 @@
+#include <git-compat-util.h>
+
+int main(int argc, char **argv)
+{
+	char *pat = "[^={} \t]+";
+	char *str = "={}\nfred";
+	regex_t r;
+	regmatch_t m[1];
+
+	if (regcomp(&r, pat, REG_EXTENDED | REG_NEWLINE))
+		die("failed regcomp() for pattern '%s'", pat);
+	if (regexec(&r, str, 1, m, 0))
+		die("no match of pattern '%s' to string '%s'", pat, str);
+
+	/* http://sourceware.org/bugzilla/show_bug.cgi?id=3957  */
+	if (m[0].rm_so == 3) /* matches '\n' when it should not */
+		die("regex bug confirmed: re-build git with NO_REGEX=1");
+
+	exit(0);
+}