From 96ef0ffaea30a11c2975e49aefe6081ee9f2fc06 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Fri, 9 Sep 2011 17:33:29 +0900
Subject: [PATCH] Rewrite QFS_FileExtension() to be more correct.

---
 libs/util/quakefs.c       | 16 ++++++++++++----
 libs/util/test/test-qfs.c | 29 ++++++++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/libs/util/quakefs.c b/libs/util/quakefs.c
index d5070bb4b..fb780d228 100644
--- a/libs/util/quakefs.c
+++ b/libs/util/quakefs.c
@@ -1337,12 +1337,20 @@ QFS_StripExtension (const char *in, char *out)
 VISIBLE const char *
 QFS_FileExtension (const char *in)
 {
-	char       *tmp;
+	const char *tmp;
+	const char *end = in + strlen (in);
 
-	if ((tmp = strrchr (in, '.')))
-		return tmp;
+	for (tmp = end; tmp != in; tmp--) {
+		if (tmp[-1] == '/')
+			return end;
+		if (tmp[-1] == '.') {
+			if (tmp - 1 == in || tmp[-2] == '/')
+				return end;
+			return tmp - 1;
+		}
+	}
 
-	return in;
+	return end;
 }
 
 VISIBLE void
diff --git a/libs/util/test/test-qfs.c b/libs/util/test/test-qfs.c
index 8d475a8a8..3dc81bd89 100644
--- a/libs/util/test/test-qfs.c
+++ b/libs/util/test/test-qfs.c
@@ -30,6 +30,22 @@ struct {
 };
 #define num_path_tests (sizeof (path_tests) / sizeof (path_tests[0]))
 
+struct {
+	const char *path;
+	int         expect_offset;
+} ext_tests[] = {
+	{"foo", 3},
+	{"foo.a", 3},
+	{"foo.a.b", 5},
+	{".foo", 4},
+	{"bar/foo", 7},
+	{"bar/foo.a", 7},
+	{"bar/foo.a.b", 9},
+	{"bar/.foo", 8},
+	{"bar.a/foo", 9},
+};
+#define num_ext_tests (sizeof (ext_tests) / sizeof (ext_tests[0]))
+
 int
 main (int argc, const char **argv)
 {
@@ -37,12 +53,23 @@ main (int argc, const char **argv)
 	int         res = 0;
 
 	for (i = 0; i < num_path_tests; i++) {
-		char       *cpath = QFS_CompressPath (path_tests[i].path);
+		const char *cpath = QFS_CompressPath (path_tests[i].path);
 		if (strcmp (cpath, path_tests[i].expect)) {
 			fprintf (stderr, "FAIL: (%zd) \"%s\" -> \"%s\", got \"%s\"\n", i,
 					 path_tests[i].path, path_tests[i].expect, cpath);
 			res = 1;
 		}
 	}
+
+	for (i = 0; i < num_ext_tests; i++) {
+		const char *ext = QFS_FileExtension (ext_tests[i].path);
+		if (ext - ext_tests[i].path != ext_tests[i].expect_offset) {
+			fprintf (stderr, "FAIL: (%zd) \"%s\" -> %d (%s), got %d (%s)\n", i,
+					 ext_tests[i].path, ext_tests[i].expect_offset,
+					 ext_tests[i].path + ext_tests[i].expect_offset,
+					 ext - ext_tests[i].path, ext);
+			res = 1;
+		}
+	}
 	return res;
 }