[PATCH] builtin-merge: avoid non-strategy git-merge commands in error message

[Miklos Vajna <vmiklos@frugalware.org>]

If an invalid strategy is supplied, like -s foobar, then git-merge
listed all git-merge-* commands. This is not perfect, since for example
git-merge-index is not a valid strategy.

These are now removed from the output by scanning the list of main
commands; if the git-merge-foo command is listed in the all_strategy
list, then it's shown, otherwise excluded. This does not exclude
commands somewhere else in the PATH, where custom strategies are
expected.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
---

On Sat, Jul 26, 2008 at 07:01:16PM +0200, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> > Hmm. So let's say ent->name is "ours.exe", ent->len is set to 4.
> >
> > Then !strncmp(ent->name, all_strategy[j].name, ent->len) will be
> > true,
> > and the command will not be added to the exclude list.
>
> What I meant is: if you change the strcmp to strncmp because one of
> the
> both strings is not supposed to be NUL terminated, you still want to
> make
> sure that one is not a strict prefix of the other.

Aah, I forgot about all_strategy[j].name is NUL terminated.

Updated patch below.

 builtin-merge.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/builtin-merge.c b/builtin-merge.c
index cdbc692..29826b1 100644
--- a/builtin-merge.c
+++ b/builtin-merge.c
@@ -88,8 +88,21 @@ static struct strategy *get_strategy(const char *name)
 			return &all_strategy[i];
 
 	if (!is_git_command(name, "git-merge-")) {
+		struct cmdnames not_strategies;
+
+		memset(&not_strategies, 0, sizeof(struct cmdnames));
+		for (i = 0; i < main_cmds.cnt; i++) {
+			int j, found = 0;
+			struct cmdname *ent = main_cmds.names[i];
+			for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
+				if (!strncmp(ent->name, all_strategy[j].name, ent->len)
+						&& !all_strategy[j].name[ent->len])
+					found = 1;
+			if (!found)
+				add_cmdname(&not_strategies, ent->name, ent->len);
+		}
 		fprintf(stderr, "Could not find merge strategy '%s'.\n\n", name);
-		list_commands("git-merge-", "strategies");
+		list_commands("git-merge-", "strategies", &not_strategies);
 		exit(1);
 	}
 
-- 
1.6.0.rc0.14.g95f8.dirty