[PATCH V2] TIG: Fix to reinstate proper operation with no arguments

From: Drew Northup <n1xim.email@gmail.com>
Date: Jul 24, 2013, 12:50 UTC
Message-ID: <1374670227-15677-1-git-send-email-n1xim.email@gmail.com>
In-Reply-To: <51EFC8B1.20405@gmail.com>

Since c7d67ab running "tig" with no options has failed with the error "tig: No revisions match the given arguments." This was due to a change in how the arguments for the back-end git call was being constructed. This change caused the blank field left in place of "(encoding_arg)" when it is empty to not overwrite "buf" which then caused the value in "buf" to be copied into dst_argv twice. The resulting git command failed if there was no available revision named "log" as shown in the trace.

>From the TIG_TRACE log:

git log log --no-color --pretty=raw --parents --parents -- fatal: bad revision 'log'

This fix works by properly and fully initializing "buf" before each use.

github issue # 167

Helped-by: Jonas Fonseca <fonseca@diku.dk>
Signed-off-by: Drew Northup <n1xim.email@gmail.com>
---

This should apply cleanly to the tig public master whether the mkstemps() patch I wrote has been applied or not. (As of the time I am sending this for review I haven't yet applied the latest fix to my mkstemps() patch that has been submitted for git itself.)

This time, knowing for sure now that format->buf is not being used in the extant code path for any other purpose, I went ahead and initialized the whole thing to be sure that we don't find any other ghosts hiding in that buffer between uses. Just initializing the first byte fixes the near term problem but does not prevent the buffer initialization issue that this bug highlighted from rising up again later on.

 tig.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tig.c b/tig.c
index ba9ba98..c65bc43 100644
--- a/tig.c
+++ b/tig.c
@@ -3104,8 +3104,12 @@ format_expand_arg(struct format_context *format, const char *name)
 static bool
 format_append_arg(struct format_context *format, const char ***dst_argv, const char *arg)
 {
+	int i;
 	format->bufpos = 0;
 
+	for (i = 0; i < SIZEOF_STR; i++)
+		format->buf[i] = 0;
+
 	while (arg) {
 		char *next = strstr(arg, "%(");
 		int len = next ? next - arg : strlen(arg);

-- 
1.8.0