[PATCH] graph: output padding for merge subsequent parents

[John Keeping <john@keeping.me.uk>]

On Wed, Feb 06, 2013 at 07:33:08PM +0100, Matthieu Moy wrote:
> John Keeping <john@keeping.me.uk> writes:
> 
> > I would argue that the line should start with "| | ", since it really is
> > just a continuation of the same commit.
> >
> > | | 
> > | | commit a393ed598e9fb11436f85bd58f1a38c82f2cadb7 (from 33e70e70c0173d634826b998bdc304f93c0966b8)
> > | | Merge: 2c1e6a3 33e70e7
> > | | Author: Matthieu Moy <Matthieu.Moy@imag.fr>
> > | | Date:   Tue Feb 5 22:05:33 2013 +0100
> 
> Yes.
> 
> I had a look at the code, I guess the call to graph_show_commit() in
> show_log() (in log-tree.c) should have called graph_show_padding() but
> didn't in this case. Then I got lost in graph.c :-(.

I think this is the correct answer.  But now I've found that "git log
--graph -c -p" doesn't indent the diff - that seems to be a separate
issue.

-- >8 --

When showing merges in git-log, the same commit is shown once for each
parent.  Combined with "--graph" this results in graph_show_commit()
being called once for each parent without graph_update() being called.

Currently graph_show_commit() does not print anything on subsequent
invocations for the same commit (this was changed by commit 656197a -
"graph.c: infinite loop in git whatchanged --graph -m" from the previous
behaviour of looping infinitely).

Change this so that if the graph code believes it has already shown the
commit it prints a single padding line.

Signed-off-by: John Keeping <john@keeping.me.uk>
---
 graph.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/graph.c b/graph.c
index 391a712..2a3fc5c 100644
--- a/graph.c
+++ b/graph.c
@@ -1227,6 +1227,16 @@ void graph_show_commit(struct git_graph *graph)
 	if (!graph)
 		return;
 
+	/*
+	 * When showing a diff of a merge against each of its parents, we
+	 * are called once for each parent without graph_update having been
+	 * called.  In this case, simply output a single padding line.
+	 */
+	if (graph_is_commit_finished(graph)) {
+		graph_show_padding(graph);
+		shown_commit_line = 1;
+	}
+
 	while (!shown_commit_line && !graph_is_commit_finished(graph)) {
 		shown_commit_line = graph_next_line(graph, &msgbuf);
 		fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
-- 
1.8.1.2