1 files changed, 20 insertions, 0 deletions
diff --git a/t/helper/test-regex.c b/t/helper/test-regex.c
new file mode 100644
index 0000000000..0dc598ecdc
--- /dev/null
+++ b/t/helper/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);
+}