[PATCH] Fix git_mkstemp to return an error when path is too long.

[Carlos Rica <jasampler@gmail.com>]

Now the function returns -2 to the caller if the given buffer
is too short to save the entire path for the temporary file.

Signed-off-by: Carlos Rica <jasampler@gmail.com>
---
 diff.c |    2 ++
 path.c |    9 ++++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/diff.c b/diff.c
index cd6b0c4..8735467 100644
--- a/diff.c
+++ b/diff.c
@@ -1694,6 +1694,8 @@ static void prep_temp_blob(struct diff_tempfile *temp,
 	int fd;

 	fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
+	if (fd == -2)
+		die("path too long for temp-file");
 	if (fd < 0)
 		die("unable to create temp-file");
 	if (write_in_full(fd, blob, size) != size)
diff --git a/path.c b/path.c
index c4ce962..f33d15d 100644
--- a/path.c
+++ b/path.c
@@ -68,7 +68,8 @@ char *git_path(const char *fmt, ...)
 }


-/* git_mkstemp() - create tmp file honoring TMPDIR variable */
+/* git_mkstemp() - create tmp file honoring TMPDIR variable.
+ * return -2 if path is too long to have it concatenated. */
 int git_mkstemp(char *path, size_t len, const char *template)
 {
 	char *env, *pch = path;
@@ -79,12 +80,14 @@ int git_mkstemp(char *path, size_t len, const char *template)
 		pch += 5;
 	} else {
 		size_t n = snprintf(pch, len, "%s/", env);
-
+		if (n >= len)
+			return -2;
 		len -= n;
 		pch += n;
 	}

-	strlcpy(pch, template, len);
+	if (strlcpy(pch, template, len) >= len)
+		return -2;

 	return mkstemp(path);
 }
-- 
1.5.0