git-merge: honor pre-merge-commit hook
git-merge does not honor the pre-commit hook when doing automatic merge commits, and for compatibility reasons this is going to stay. Introduce a pre-merge-commit hook which is called for an automatic merge commit just like pre-commit is called for a non-automatic merge commit (or any other commit). [js: * renamed hook from "pre-merge" to "pre-merge-commit" * only discard the index if the hook is actually present * expanded githooks documentation entry * clarified that hook should write messages to stderr * squashed test changes from the original series' patch 4/4 * modified tests to follow new pattern from this series' patch 1/4 * added a test case for non-executable merge hooks * added a test case for failed merges * when testing that the merge hook did not run, make sure we actually have a merge to perform (by resetting the "side" branch to its original state). * reworded commit message ] Improved-by: Martin Ågren <martin.agren@gmail.com> Signed-off-by: Michael J Gruber <git@grubix.eu> Signed-off-by: Martin Ågren <martin.agren@gmail.com> Signed-off-by: Josh Steadmon <steadmon@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Michael J Gruber committed
Aug 7, 2019 at 11:57 UTC
6098817fd7f64209664c701df30096dc0f4fb876
4 files changed
+129
-1
Documentation/githooks.txt
+21
@@ -103,6 +103,27 @@ The default 'pre-commit' hook, when enabled--and with the
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`hooks.allownonascii` config option unset or set to false--prevents
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the use of non-ASCII filenames.
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+pre-merge-commit
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+~~~~~~~~~~~~~~~~
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+
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+This hook is invoked by linkgit:git-merge[1]. It takes no parameters, and is
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+invoked after the merge has been carried out successfully and before
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+obtaining the proposed commit log message to
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+make a commit. Exiting with a non-zero status from this script
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+causes the `git merge` command to abort before creating a commit.
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+
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+The default 'pre-merge-commit' hook, when enabled, runs the
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+'pre-commit' hook, if the latter is enabled.
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+
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+This hook is invoked with the environment variable
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+`GIT_EDITOR=:` if the command will not bring up an editor
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+to modify the commit message.
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+
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+If the merge cannot be carried out automatically, the conflicts
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+need to be resolved and the result committed separately (see
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+linkgit:git-merge[1]). At that point, this hook will not be executed,
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+but the 'pre-commit' hook will, if it is enabled.
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+
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prepare-commit-msg
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~~~~~~~~~~~~~~~~~~
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builtin/merge.c
+12
@@ -816,6 +816,18 @@ static void write_merge_heads(struct commit_list *);
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static void prepare_to_commit(struct commit_list *remoteheads)
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{
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struct strbuf msg = STRBUF_INIT;
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+ const char *index_file = get_index_file();
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+
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+ if (run_commit_hook(0 < option_edit, index_file, "pre-merge-commit", NULL))
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+ abort_commit(remoteheads, NULL);
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+ /*
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+ * Re-read the index as pre-merge-commit hook could have updated it,
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+ * and write it out as a tree. We must do this before we invoke
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+ * the editor and after we invoke run_status above.
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+ */
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+ if (find_hook("pre-merge-commit"))
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+ discard_cache();
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+ read_cache_from(index_file);
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strbuf_addbuf(&msg, &merge_msg);
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if (squash)
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BUG("the control must not reach here under --squash");
t/t7503-pre-commit-and-pre-merge-commit-hooks.sh
renamed
+83
-1
@@ -1,11 +1,12 @@
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#!/bin/sh
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-test_description='pre-commit hook'
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+test_description='pre-commit and pre-merge-commit hooks'
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. ./test-lib.sh
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HOOKDIR="$(git rev-parse --git-dir)/hooks"
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PRECOMMIT="$HOOKDIR/pre-commit"
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+PREMERGE="$HOOKDIR/pre-merge-commit"
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# Prepare sample scripts that write their $0 to actual_hooks
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test_expect_success 'sample script setup' '
@@ -34,6 +35,30 @@ test_expect_success 'sample script setup' '
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EOF
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'
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+test_expect_success 'root commit' '
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+ echo "root" >file &&
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+ git add file &&
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+ git commit -m "zeroth" &&
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+ git checkout -b side &&
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+ echo "foo" >foo &&
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+ git add foo &&
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+ git commit -m "make it non-ff" &&
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+ git branch side-orig side &&
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+ git checkout master
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+'
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+
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+test_expect_success 'setup conflicting branches' '
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+ test_when_finished "git checkout master" &&
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+ git checkout -b conflicting-a master &&
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+ echo a >conflicting &&
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+ git add conflicting &&
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+ git commit -m conflicting-a &&
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+ git checkout -b conflicting-b master &&
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+ echo b >conflicting &&
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+ git add conflicting &&
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+ git commit -m conflicting-b
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+'
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+
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test_expect_success 'with no hook' '
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test_when_finished "rm -f actual_hooks" &&
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echo "foo" >file &&
@@ -42,6 +67,15 @@ test_expect_success 'with no hook' '
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test_path_is_missing actual_hooks
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'
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+test_expect_success 'with no hook (merge)' '
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+ test_when_finished "rm -f actual_hooks" &&
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+ git branch -f side side-orig &&
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+ git checkout side &&
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+ git merge -m "merge master" master &&
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+ git checkout master &&
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+ test_path_is_missing actual_hooks
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+'
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+
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test_expect_success '--no-verify with no hook' '
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test_when_finished "rm -f actual_hooks" &&
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echo "bar" >file &&
@@ -60,6 +94,34 @@ test_expect_success 'with succeeding hook' '
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test_cmp expected_hooks actual_hooks
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'
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+test_expect_success 'with succeeding hook (merge)' '
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+ test_when_finished "rm -f \"$PREMERGE\" expected_hooks actual_hooks" &&
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+ cp "$HOOKDIR/success.sample" "$PREMERGE" &&
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+ echo "$PREMERGE" >expected_hooks &&
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+ git checkout side &&
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+ git merge -m "merge master" master &&
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+ git checkout master &&
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+ test_cmp expected_hooks actual_hooks
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+'
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+
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+test_expect_success 'automatic merge fails; both hooks are available' '
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+ test_when_finished "rm -f \"$PREMERGE\" \"$PRECOMMIT\"" &&
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+ test_when_finished "rm -f expected_hooks actual_hooks" &&
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+ test_when_finished "git checkout master" &&
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+ cp "$HOOKDIR/success.sample" "$PREMERGE" &&
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+ cp "$HOOKDIR/success.sample" "$PRECOMMIT" &&
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+
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+ git checkout conflicting-a &&
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+ test_must_fail git merge -m "merge conflicting-b" conflicting-b &&
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+ test_path_is_missing actual_hooks &&
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+
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+ echo "$PRECOMMIT" >expected_hooks &&
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+ echo a+b >conflicting &&
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+ git add conflicting &&
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+ git commit -m "resolve conflict" &&
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+ test_cmp expected_hooks actual_hooks
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+'
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+
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test_expect_success '--no-verify with succeeding hook' '
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test_when_finished "rm -f \"$PRECOMMIT\" actual_hooks" &&
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cp "$HOOKDIR/success.sample" "$PRECOMMIT" &&
@@ -88,6 +150,16 @@ test_expect_success '--no-verify with failing hook' '
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test_path_is_missing actual_hooks
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'
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+test_expect_success 'with failing hook (merge)' '
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+ test_when_finished "rm -f \"$PREMERGE\" expected_hooks actual_hooks" &&
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+ cp "$HOOKDIR/fail.sample" "$PREMERGE" &&
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+ echo "$PREMERGE" >expected_hooks &&
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+ git checkout side &&
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+ test_must_fail git merge -m "merge master" master &&
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+ git checkout master &&
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+ test_cmp expected_hooks actual_hooks
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+'
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+
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test_expect_success POSIXPERM 'with non-executable hook' '
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test_when_finished "rm -f \"$PRECOMMIT\" actual_hooks" &&
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cp "$HOOKDIR/non-exec.sample" "$PRECOMMIT" &&
@@ -106,6 +178,16 @@ test_expect_success POSIXPERM '--no-verify with non-executable hook' '
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test_path_is_missing actual_hooks
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'
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+test_expect_success POSIXPERM 'with non-executable hook (merge)' '
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+ test_when_finished "rm -f \"$PREMERGE\" actual_hooks" &&
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+ cp "$HOOKDIR/non-exec.sample" "$PREMERGE" &&
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+ git branch -f side side-orig &&
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+ git checkout side &&
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+ git merge -m "merge master" master &&
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+ git checkout master &&
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+ test_path_is_missing actual_hooks
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+'
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+
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test_expect_success 'with hook requiring GIT_PREFIX' '
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test_when_finished "rm -rf \"$PRECOMMIT\" expected_hooks actual_hooks success" &&
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cp "$HOOKDIR/require-prefix.sample" "$PRECOMMIT" &&
templates/hooks--pre-merge-commit.sample
new
+13
@@ -0,0 +1,13 @@
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+#!/bin/sh
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+#
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+# An example hook script to verify what is about to be committed.
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+# Called by "git merge" with no arguments. The hook should
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+# exit with non-zero status after issuing an appropriate message to
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+# stderr if it wants to stop the merge commit.
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+#
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+# To enable this hook, rename this file to "pre-merge-commit".
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+
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+. git-sh-setup
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+test -x "$GIT_DIR/hooks/pre-commit" &&
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+ exec "$GIT_DIR/hooks/pre-commit"
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+: