fix GIT_TRACE segfault with shell-quoted aliases

The alias argv comes from the split_cmdline function, which
splits the config text for the alias into an array of
strings. It returns the number of elements in the array, but
does not actually put a NULL at the end of the array.
Later, the trace function tries to print this argv and
assumes that it has the trailing NULL.

The split_cmdline function is probably at fault, since argv
lists almost always end with a NULL signal. This patch adds
one, in addition to the returned count; this doesn't hurt
the other callers at all, since they were presumably using
the count already (and will never look at the NULL).

While we're there and using ALLOC_GROW, let's clean up the
other manual grow.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/alias.c b/alias.c
index ccb1108c94436035d0da8b1d6f08f859b68294a3..4f4d0141cdca47cc2fd5062624e3a7b643d0793c 100644 (file)
--- a/alias.c
+++ b/alias.c
@@ -38,10 +38,7 @@ int split_cmdline(char *cmdline, const char ***argv)
                        while (cmdline[++src]
                                        && isspace(cmdline[src]))
                                ; /* skip */
-                       if (count >= size) {
-                               size += 16;
-                               *argv = xrealloc(*argv, sizeof(char*) * size);
-                       }
+                       ALLOC_GROW(*argv, count+1, size);
                        (*argv)[count++] = cmdline + dst;
                } else if (!quoted && (c == '\'' || c == '"')) {
                        quoted = c;
@@ -72,6 +69,9 @@ int split_cmdline(char *cmdline, const char ***argv)
                return error("unclosed quote");
        }
 
+       ALLOC_GROW(*argv, count+1, size);
+       (*argv)[count] = NULL;
+
        return count;
 }