From e95e481f9e6e4dfe62380ccc8a47acf446403a94 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 17 Aug 2019 11:41:40 -0700 Subject: merge-recursive: avoid losing output and leaking memory holding that output If opt->buffer_output is less than 2, then merge_trees(), merge_recursive(), and merge_recursive_generic() are all supposed to flush the opt->obuf output buffer to stdout and release any memory it holds. merge_trees() did not do this. Move the logic that handles this for merge_recursive_internal() to merge_finalize() so that all three methods handle this requirement. Note that this bug didn't cause any problems currently, because there are only two callers of merge_trees() right now (a git grep for 'merge_trees(' is misleading because builtin/merge-tree.c also defines a 'merge_tree' function that is unrelated), and only one of those is called with buffer_output less than 2 (builtin/checkout.c), but it set opt->verbosity to 0, for which there is only currently one non-error message that would be shown: "Already up to date!". However, that one message can only occur when the merge is utterly trivial (the merge base tree exactly matches the merge tree), and builtin/checkout.c already attempts a trivial merge via unpack_trees() before falling back to merge_trees(). Also, if opt->buffer_output is 2, then the caller is responsible to handle showing any output in opt->obuf and for free'ing it. This requirement might be easy to overlook, so add a comment to merge-recursive.h pointing it out. (There are currently two callers that set buffer_output to 2, both in sequencer.c, and both of which handle this correctly.) Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- merge-recursive.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'merge-recursive.h') diff --git a/merge-recursive.h b/merge-recursive.h index 9e040608fe..933d6e7642 100644 --- a/merge-recursive.h +++ b/merge-recursive.h @@ -38,7 +38,8 @@ struct merge_options { /* console output related options */ int verbosity; unsigned buffer_output; /* 1: output at end, 2: keep buffered */ - struct strbuf obuf; /* output buffer */ + struct strbuf obuf; /* output buffer; if buffer_output == 2, caller + * must handle and call strbuf_release */ /* miscellaneous control options */ const char *subtree_shift; -- cgit v1.3-5-g9baa