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From: Elijah Newren <newren@gmail.com>
To: git@vger.kernel.org
Cc: Junio C Hamano <gitster@pobox.com>,
	Johannes Schindelin <Johannes.Schindelin@gmx.de>,
	Derrick Stolee <stolee@gmail.com>,
	Elijah Newren <newren@gmail.com>
Subject: [PATCH v3 20/24] merge-recursive: avoid losing output and leaking memory holding that output
Date: Thu, 15 Aug 2019 14:40:49 -0700
Message-ID: <20190815214053.16594-21-newren@gmail.com> (raw)
In-Reply-To: <20190815214053.16594-1-newren@gmail.com>

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 <newren@gmail.com>
---
 merge-recursive.c | 6 +++---
 merge-recursive.h | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/merge-recursive.c b/merge-recursive.c
index db2c544d0b..b4334d0506 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -3603,9 +3603,6 @@ static int merge_recursive_internal(struct merge_options *opt,
 		commit_list_insert(h1, &(*result)->parents);
 		commit_list_insert(h2, &(*result)->parents->next);
 	}
-	flush_output(opt);
-	if (!opt->call_depth && opt->buffer_output < 2)
-		strbuf_release(&opt->obuf);
 	return clean;
 }
 
@@ -3625,6 +3622,9 @@ static int merge_start(struct merge_options *opt, struct tree *head)
 
 static void merge_finalize(struct merge_options *opt)
 {
+	flush_output(opt);
+	if (!opt->call_depth && opt->buffer_output < 2)
+		strbuf_release(&opt->obuf);
 	if (show(opt, 2))
 		diff_warn_rename_limit("merge.renamelimit",
 				       opt->needed_rename_limit, 0);
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;
-- 
2.23.0.rc2.32.g2123e9e4e4


  parent reply index

Thread overview: 142+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-25 17:45 [PATCH 00/19] Cleanup merge API Elijah Newren
2019-07-25 17:45 ` [PATCH 01/19] merge-recursive: fix minor memory leak in error condition Elijah Newren
2019-07-25 17:45 ` [PATCH 02/19] merge-recursive: remove another implicit dependency on the_repository Elijah Newren
2019-07-25 17:45 ` [PATCH 03/19] Ensure index matches head before invoking merge machinery, round N Elijah Newren
2019-07-25 19:41   ` Johannes Schindelin
2019-07-25 19:58     ` Elijah Newren
2019-07-26 11:23       ` Johannes Schindelin
2019-07-25 17:45 ` [PATCH 04/19] merge-recursive: exit early if index != head Elijah Newren
2019-07-25 19:51   ` Johannes Schindelin
2019-07-25 20:12     ` Elijah Newren
2019-07-25 17:45 ` [PATCH 05/19] merge-recursive: don't force external callers to do our logging Elijah Newren
2019-07-25 17:45 ` [PATCH 06/19] Change call signature of write_tree_from_memory() Elijah Newren
2019-07-25 19:55   ` Johannes Schindelin
2019-07-26  4:58     ` Elijah Newren
2019-07-25 17:45 ` [PATCH 07/19] Move write_tree_from_memory() from merge-recursive to cache-tree Elijah Newren
2019-07-25 17:46 ` [PATCH 08/19] merge-recursive: fix some overly long lines Elijah Newren
2019-07-25 17:46 ` [PATCH 09/19] merge-recursive: use common name for ancestors/common/base_list Elijah Newren
2019-07-25 17:46 ` [PATCH 10/19] merge-recursive: rename 'mrtree' to 'result_tree', for clarity Elijah Newren
2019-07-25 20:02   ` Johannes Schindelin
2019-07-25 17:46 ` [PATCH 11/19] merge-recursive: rename merge_options argument to opt in header Elijah Newren
2019-07-25 17:46 ` [PATCH 12/19] merge-recursive: move some definitions around to clean up the header Elijah Newren
2019-07-25 17:46 ` [PATCH 13/19] merge-recursive: consolidate unnecessary fields in merge_options Elijah Newren
2019-07-25 17:46 ` [PATCH 14/19] merge-recursive: comment and reorder the merge_options fields Elijah Newren
2019-07-25 17:46 ` [PATCH 15/19] merge-recursive: split internal fields into a separate struct Elijah Newren
2019-07-25 20:12   ` Johannes Schindelin
2019-07-25 20:27     ` Elijah Newren
2019-07-26 11:25       ` Johannes Schindelin
2019-07-26 15:30         ` Elijah Newren
2019-07-25 17:46 ` [PATCH 16/19] merge-recursive: alphabetize include list Elijah Newren
2019-07-25 17:46 ` [PATCH 17/19] merge-recursive: rename MERGE_RECURSIVE_* to MERGE_VARIANT_* Elijah Newren
2019-07-25 17:46 ` [PATCH 18/19] merge-recursive: be consistent with assert Elijah Newren
2019-07-25 17:46 ` [PATCH 19/19] merge-recursive: provide a better label for diff3 common ancestor Elijah Newren
2019-07-25 20:28   ` Johannes Schindelin
2019-07-25 18:12 ` [PATCH 00/19] Cleanup merge API Junio C Hamano
2019-07-25 19:06   ` Elijah Newren
2019-07-25 22:50     ` Junio C Hamano
2019-07-26 14:07       ` Johannes Schindelin
2019-07-25 19:15 ` Johannes Schindelin
2019-07-26 15:15   ` Elijah Newren
2019-07-26 15:52 ` [PATCH v2 00/20] " Elijah Newren
2019-07-26 15:52   ` [PATCH v2 01/20] merge-recursive: fix minor memory leak in error condition Elijah Newren
2019-07-26 18:31     ` Junio C Hamano
2019-07-26 23:19       ` Elijah Newren
2019-07-29 14:13       ` Derrick Stolee
2019-07-26 15:52   ` [PATCH v2 02/20] merge-recursive: remove another implicit dependency on the_repository Elijah Newren
2019-07-26 18:42     ` Junio C Hamano
2019-07-26 15:52   ` [PATCH v2 03/20] Ensure index matches head before invoking merge machinery, round N Elijah Newren
2019-07-26 19:14     ` Junio C Hamano
2019-07-26 23:22       ` Elijah Newren
2019-07-26 15:52   ` [PATCH v2 04/20] merge-recursive: exit early if index != head Elijah Newren
2019-07-26 19:32     ` Junio C Hamano
2019-07-26 23:26       ` Elijah Newren
2019-07-29 15:56         ` Junio C Hamano
2019-07-26 15:52   ` [PATCH v2 05/20] merge-recursive: remove useless parameter in merge_trees() Elijah Newren
2019-07-26 19:37     ` Junio C Hamano
2019-07-26 15:52   ` [PATCH v2 06/20] merge-recursive: don't force external callers to do our logging Elijah Newren
2019-07-26 19:57     ` Junio C Hamano
2019-07-26 23:28       ` Elijah Newren
2019-07-26 15:52   ` [PATCH v2 07/20] Use write_index_as_tree() in lieu of write_tree_from_memory() Elijah Newren
2019-07-26 20:11     ` Junio C Hamano
2019-07-26 23:39       ` Elijah Newren
2019-07-29  4:46         ` Junio C Hamano
2019-07-26 15:52   ` [PATCH v2 08/20] merge-recursive: fix some overly long lines Elijah Newren
2019-07-26 15:52   ` [PATCH v2 09/20] merge-recursive: use common name for ancestors/common/base_list Elijah Newren
2019-07-26 15:52   ` [PATCH v2 10/20] merge-recursive: rename 'mrtree' to 'result_tree', for clarity Elijah Newren
2019-07-26 15:52   ` [PATCH v2 11/20] merge-recursive: rename merge_options argument to opt in header Elijah Newren
2019-07-26 15:52   ` [PATCH v2 12/20] merge-recursive: move some definitions around to clean up the header Elijah Newren
2019-07-26 15:52   ` [PATCH v2 13/20] merge-recursive: consolidate unnecessary fields in merge_options Elijah Newren
2019-07-26 15:52   ` [PATCH v2 14/20] merge-recursive: comment and reorder the merge_options fields Elijah Newren
2019-07-26 15:52   ` [PATCH v2 15/20] merge-recursive: avoid losing output and leaking memory holding that output Elijah Newren
2019-07-26 15:52   ` [PATCH v2 16/20] merge-recursive: split internal fields into a separate struct Elijah Newren
2019-07-26 15:52   ` [PATCH v2 17/20] merge-recursive: alphabetize include list Elijah Newren
2019-07-26 15:52   ` [PATCH v2 18/20] merge-recursive: rename MERGE_RECURSIVE_* to MERGE_VARIANT_* Elijah Newren
2019-07-26 15:52   ` [PATCH v2 19/20] merge-recursive: be consistent with assert Elijah Newren
2019-07-26 15:52   ` [PATCH v2 20/20] merge-recursive: provide a better label for diff3 common ancestor Elijah Newren
2019-08-15 21:40   ` [PATCH v3 00/24] Clean up merge API Elijah Newren
2019-08-15 21:40     ` [PATCH v3 01/24] merge-recursive: be consistent with assert Elijah Newren
2019-08-15 21:40     ` [PATCH v3 02/24] checkout: provide better conflict hunk description with detached HEAD Elijah Newren
2019-08-15 21:40     ` [PATCH v3 03/24] merge-recursive: enforce opt->ancestor != NULL when calling merge_trees() Elijah Newren
2019-08-16 21:05       ` Junio C Hamano
2019-08-15 21:40     ` [PATCH v3 04/24] merge-recursive: provide a better label for diff3 common ancestor Elijah Newren
2019-08-16 21:33       ` Junio C Hamano
2019-08-16 22:39         ` Elijah Newren
2019-08-15 21:40     ` [PATCH v3 05/24] merge-recursive: introduce an enum for detect_directory_renames values Elijah Newren
2019-08-15 21:40     ` [PATCH v3 06/24] merge-recursive: future-proof update_file_flags() against memory leaks Elijah Newren
2019-08-15 21:40     ` [PATCH v3 07/24] merge-recursive: remove another implicit dependency on the_repository Elijah Newren
2019-08-15 21:40     ` [PATCH v3 08/24] Ensure index matches head before invoking merge machinery, round N Elijah Newren
2019-08-15 21:40     ` [PATCH v3 09/24] merge-recursive: exit early if index != head Elijah Newren
2019-08-15 21:40     ` [PATCH v3 10/24] merge-recursive: remove useless parameter in merge_trees() Elijah Newren
2019-08-15 21:40     ` [PATCH v3 11/24] merge-recursive: don't force external callers to do our logging Elijah Newren
2019-08-15 21:40     ` [PATCH v3 12/24] cache-tree: share code between functions writing an index as a tree Elijah Newren
2019-08-16 22:01       ` Junio C Hamano
2019-08-16 22:39         ` Elijah Newren
2019-08-15 21:40     ` [PATCH v3 13/24] merge-recursive: fix some overly long lines Elijah Newren
2019-08-15 21:40     ` [PATCH v3 14/24] merge-recursive: use common name for ancestors/common/base_list Elijah Newren
2019-08-15 21:40     ` [PATCH v3 15/24] merge-recursive: rename 'mrtree' to 'result_tree', for clarity Elijah Newren
2019-08-15 21:40     ` [PATCH v3 16/24] merge-recursive: rename merge_options argument to opt in header Elijah Newren
2019-08-15 21:40     ` [PATCH v3 17/24] merge-recursive: move some definitions around to clean up the header Elijah Newren
2019-08-15 21:40     ` [PATCH v3 18/24] merge-recursive: consolidate unnecessary fields in merge_options Elijah Newren
2019-08-16 22:14       ` Junio C Hamano
2019-08-16 22:59         ` Elijah Newren
2019-08-16 23:24           ` Junio C Hamano
2019-08-15 21:40     ` [PATCH v3 19/24] merge-recursive: comment and reorder the merge_options fields Elijah Newren
2019-08-15 21:40     ` Elijah Newren [this message]
2019-08-15 21:40     ` [PATCH v3 21/24] merge-recursive: split internal fields into a separate struct Elijah Newren
2019-08-16 21:19       ` SZEDER Gábor
2019-08-16 23:00         ` Elijah Newren
2019-08-16 22:17       ` Junio C Hamano
2019-08-15 21:40     ` [PATCH v3 22/24] merge-recursive: rename MERGE_RECURSIVE_* to MERGE_VARIANT_* Elijah Newren
2019-08-15 21:40     ` [PATCH v3 23/24] merge-recursive: add sanity checks for relevant merge_options Elijah Newren
2019-08-16 19:52       ` Junio C Hamano
2019-08-16 22:08         ` Elijah Newren
2019-08-16 23:15           ` Junio C Hamano
2019-08-16 19:59       ` Junio C Hamano
2019-08-16 22:09         ` Elijah Newren
2019-08-15 21:40     ` [PATCH v3 24/24] merge-recursive: alphabetize include list Elijah Newren
2019-08-17 18:41     ` [PATCH v4 00/24] Clean up merge API Elijah Newren
2019-08-17 18:41       ` [PATCH v4 01/24] merge-recursive: be consistent with assert Elijah Newren
2019-08-17 18:41       ` [PATCH v4 02/24] checkout: provide better conflict hunk description with detached HEAD Elijah Newren
2019-08-17 18:41       ` [PATCH v4 03/24] merge-recursive: enforce opt->ancestor != NULL when calling merge_trees() Elijah Newren
2019-08-17 18:41       ` [PATCH v4 04/24] merge-recursive: provide a better label for diff3 common ancestor Elijah Newren
2019-08-17 18:41       ` [PATCH v4 05/24] merge-recursive: introduce an enum for detect_directory_renames values Elijah Newren
2019-08-17 18:41       ` [PATCH v4 06/24] merge-recursive: future-proof update_file_flags() against memory leaks Elijah Newren
2019-08-17 18:41       ` [PATCH v4 07/24] merge-recursive: remove another implicit dependency on the_repository Elijah Newren
2019-08-17 18:41       ` [PATCH v4 08/24] Ensure index matches head before invoking merge machinery, round N Elijah Newren
2019-08-17 18:41       ` [PATCH v4 09/24] merge-recursive: exit early if index != head Elijah Newren
2019-08-17 18:41       ` [PATCH v4 10/24] merge-recursive: remove useless parameter in merge_trees() Elijah Newren
2019-08-17 18:41       ` [PATCH v4 11/24] merge-recursive: don't force external callers to do our logging Elijah Newren
2019-08-17 18:41       ` [PATCH v4 12/24] cache-tree: share code between functions writing an index as a tree Elijah Newren
2019-08-17 18:41       ` [PATCH v4 13/24] merge-recursive: fix some overly long lines Elijah Newren
2019-08-17 18:41       ` [PATCH v4 14/24] merge-recursive: use common name for ancestors/common/base_list Elijah Newren
2019-08-17 18:41       ` [PATCH v4 15/24] merge-recursive: rename 'mrtree' to 'result_tree', for clarity Elijah Newren
2019-08-17 18:41       ` [PATCH v4 16/24] merge-recursive: rename merge_options argument to opt in header Elijah Newren
2019-08-17 18:41       ` [PATCH v4 17/24] merge-recursive: move some definitions around to clean up the header Elijah Newren
2019-08-17 18:41       ` [PATCH v4 18/24] merge-recursive: consolidate unnecessary fields in merge_options Elijah Newren
2019-08-17 18:41       ` [PATCH v4 19/24] merge-recursive: comment and reorder the merge_options fields Elijah Newren
2019-08-17 18:41       ` [PATCH v4 20/24] merge-recursive: avoid losing output and leaking memory holding that output Elijah Newren
2019-08-17 18:41       ` [PATCH v4 21/24] merge-recursive: split internal fields into a separate struct Elijah Newren
2019-08-19 17:17         ` Junio C Hamano
2019-08-17 18:41       ` [PATCH v4 22/24] merge-recursive: rename MERGE_RECURSIVE_* to MERGE_VARIANT_* Elijah Newren
2019-08-17 18:41       ` [PATCH v4 23/24] merge-recursive: add sanity checks for relevant merge_options Elijah Newren
2019-08-17 18:41       ` [PATCH v4 24/24] merge-recursive: alphabetize include list Elijah Newren

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