[PATCH 1/2] submodule: ignore trailing slash on superproject URL

[Stefan Beller <sbeller@google.com>]

Before 63e95beb0 (2016-04-15, submodule: port resolve_relative_url from
shell to C), it did not matter if the superprojects URL had a trailing
slash or not. It was just chopped off as one of the first steps
(The "remoteurl=${remoteurl%/}" near the beginning of
resolve_relative_url(), which was removed in said commit).

When porting this to the C version, an off-by-one error was introduced
and we did not check the actual last character to be a slash, but the
NULL delimiter.

Reintroduce the behavior from before 63e95beb0, to ignore the trailing
slash.

Reported-by: <venv21@gmail.com>
Helped-by: Dennis Kaarsemaker <dennis@kaarsemaker.net>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 builtin/submodule--helper.c | 6 ++++--
 t/t0060-path-utils.sh       | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 444ec06..a7841a5 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -95,6 +95,8 @@ static int chop_last_dir(char **remoteurl, int is_relative)
  * NEEDSWORK: This works incorrectly on the domain and protocol part.
  * remote_url      url              outcome          expectation
  * http://a.com/b  ../c             http://a.com/c   as is
+ * http://a.com/b/ ../c             http://a.com/c   same as previous line, but
+ *                                                   ignore trailing slash in url
  * http://a.com/b  ../../c          http://c         error out
  * http://a.com/b  ../../../c       http:/c          error out
  * http://a.com/b  ../../../../c    http:c           error out
@@ -113,8 +115,8 @@ static char *relative_url(const char *remote_url,
 	struct strbuf sb = STRBUF_INIT;
 	size_t len = strlen(remoteurl);
 
-	if (is_dir_sep(remoteurl[len]))
-		remoteurl[len] = '\0';
+	if (is_dir_sep(remoteurl[len-1]))
+		remoteurl[len-1] = '\0';
 
 	if (!url_is_local_not_ssh(remoteurl) || is_absolute_path(remoteurl))
 		is_relative = 0;
diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index bf2deee..82b98f8 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -319,6 +319,7 @@ test_submodule_relative_url "../" "foo/bar" "../submodule" "../foo/submodule"
 test_submodule_relative_url "../" "foo" "../submodule" "../submodule"
 
 test_submodule_relative_url "(null)" "../foo/bar" "../sub/a/b/c" "../foo/sub/a/b/c"
+test_submodule_relative_url "(null)" "../foo/bar/" "../sub/a/b/c" "../foo/sub/a/b/c"
 test_submodule_relative_url "(null)" "../foo/bar" "../submodule" "../foo/submodule"
 test_submodule_relative_url "(null)" "../foo/submodule" "../submodule" "../foo/submodule"
 test_submodule_relative_url "(null)" "../foo" "../submodule" "../submodule"
-- 
2.10.1.382.ga23ca1b.dirty