git-commit: add a prepare-commit-msg hook
The prepare-commit-msg hook is run whenever a "fresh" commit message is prepared, just before it is shown in the editor (if it is). Its purpose is to modify the commit message in-place. It takes one to three parameters. The first is the name of the file that the commit log message. The second is the source of the commit message, and can be: "message" (if a -m or -F option was given); "template" (if a -t option was given or the configuration option commit.template is set); "merge" (if the commit is a merge or a .git/MERGE_MSG file exists); "squash" (if a .git/SQUASH_MSG file exists); or "commit", followed by a commit SHA1 as the third parameter (if a -c, -C or --amend option was given). If its exit status is non-zero, git-commit will abort. The hook is not suppressed by the --no-verify option, so it should not be used as a replacement for the pre-commit hook. The sample prepare-commit-msg comments out the `Conflicts:` part of a merge's commit message; other examples are commented out, including adding a Signed-off-by line at the bottom of the commit messsage, that the user can then edit or discard altogether. Signed-off-by: Paolo Bonzini <bonzini@gnu.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Paolo Bonzini committed
Feb 5, 2008 at 08:04 UTC
8089c85bcba89464b9b2a32fa948ed85eb367e70
6 files changed
+242
-2
Documentation/git-commit.txt
+2
-2
@@ -280,8 +280,8 @@ order).
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HOOKS
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-----
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-This command can run `commit-msg`, `pre-commit`, and
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-`post-commit` hooks. See link:hooks.html[hooks] for more
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+This command can run `commit-msg`, `prepare-commit-msg`, `pre-commit`,
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+and `post-commit` hooks. See link:hooks.html[hooks] for more
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information.
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Documentation/hooks.txt
+25
@@ -65,6 +65,31 @@ All the `git-commit` hooks are invoked with the environment
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variable `GIT_EDITOR=:` if the command will not bring up an editor
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to modify the commit message.
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+prepare-commit-msg
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+------------------
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+
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+This hook is invoked by `git-commit` right after preparing the
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+default log message, and before the editor is started.
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+
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+It takes one to three parameters. The first is the name of the file
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+that the commit log message. The second is the source of the commit
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+message, and can be: `message` (if a `\-m` or `\-F` option was
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+given); `template` (if a `\-t` option was given or the
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+configuration option `commit.template` is set); `merge` (if the
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+commit is a merge or a `.git/MERGE_MSG` file exists); `squash`
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+(if a `.git/SQUASH_MSG` file exists); or `commit`, followed by
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+a commit SHA1 (if a `\-c`, `\-C` or `\--amend` option was given).
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+
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+If the exit status is non-zero, `git-commit` will abort.
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+
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+The purpose of the hook is to edit the message file in place, and
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+it is not suppressed by the `\--no-verify` option. A non-zero exit
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+means a failure of the hook and aborts the commit. It should not
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+be used as replacement for pre-commit hook.
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+
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+The sample `prepare-commit-msg` hook that comes with git comments
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+out the `Conflicts:` part of a merge's commit message.
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+
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commit-msg
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----------
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builtin-commit.c
+21
@@ -394,6 +394,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
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struct strbuf sb;
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char *buffer;
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FILE *fp;
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+ const char *hook_arg1 = NULL;
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+ const char *hook_arg2 = NULL;
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if (!no_verify && run_hook(index_file, "pre-commit", NULL))
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return 0;
@@ -401,32 +403,47 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
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strbuf_init(&sb, 0);
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if (message.len) {
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strbuf_addbuf(&sb, &message);
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+ hook_arg1 = "message";
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} else if (logfile && !strcmp(logfile, "-")) {
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if (isatty(0))
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fprintf(stderr, "(reading log message from standard input)\n");
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if (strbuf_read(&sb, 0, 0) < 0)
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die("could not read log from standard input");
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+ hook_arg1 = "message";
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} else if (logfile) {
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if (strbuf_read_file(&sb, logfile, 0) < 0)
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die("could not read log file '%s': %s",
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logfile, strerror(errno));
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+ hook_arg1 = "message";
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} else if (use_message) {
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buffer = strstr(use_message_buffer, "\n\n");
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if (!buffer || buffer[2] == '\0')
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die("commit has empty message");
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strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
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+ hook_arg1 = "commit";
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+ hook_arg2 = use_message;
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} else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
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if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
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die("could not read MERGE_MSG: %s", strerror(errno));
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+ hook_arg1 = "merge";
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} else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
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if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
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die("could not read SQUASH_MSG: %s", strerror(errno));
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+ hook_arg1 = "squash";
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} else if (template_file && !stat(template_file, &statbuf)) {
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if (strbuf_read_file(&sb, template_file, 0) < 0)
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die("could not read %s: %s",
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template_file, strerror(errno));
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+ hook_arg1 = "template";
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}
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+ /*
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+ * This final case does not modify the template message,
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+ * it just sets the argument to the prepare-commit-msg hook.
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+ */
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+ else if (in_merge)
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+ hook_arg1 = "merge";
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+
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fp = fopen(git_path(commit_editmsg), "w");
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if (fp == NULL)
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die("could not open %s", git_path(commit_editmsg));
@@ -534,6 +551,10 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
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return 0;
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}
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+ if (run_hook(index_file, "prepare-commit-msg",
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+ git_path(commit_editmsg), hook_arg1, hook_arg2, NULL))
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+ return 0;
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+
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if (use_editor) {
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char index[PATH_MAX];
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const char *env[2] = { index, NULL };
t/t7505-prepare-commit-msg-hook.sh
new
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@@ -0,0 +1,155 @@
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+#!/bin/sh
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+
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+test_description='prepare-commit-msg hook'
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+
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+. ./test-lib.sh
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+
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+test_expect_success 'with no hook' '
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+
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+ echo "foo" > file &&
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+ git add file &&
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+ git commit -m "first"
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+
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+'
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+
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+# set up fake editor for interactive editing
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+cat > fake-editor <<'EOF'
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+#!/bin/sh
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+exit 0
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+EOF
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+chmod +x fake-editor
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+FAKE_EDITOR="$(pwd)/fake-editor"
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+export FAKE_EDITOR
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+
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+# now install hook that always succeeds and adds a message
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+HOOKDIR="$(git rev-parse --git-dir)/hooks"
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+HOOK="$HOOKDIR/prepare-commit-msg"
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+mkdir -p "$HOOKDIR"
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+cat > "$HOOK" <<'EOF'
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+#!/bin/sh
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+if test "$2" = commit; then
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+ source=$(git-rev-parse "$3")
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+else
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+ source=${2-default}
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+fi
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+if test "$GIT_EDITOR" = :; then
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+ sed -e "1s/.*/$source (no editor)/" "$1" > msg.tmp
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+else
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+ sed -e "1s/.*/$source/" "$1" > msg.tmp
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+fi
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+mv msg.tmp "$1"
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+exit 0
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+EOF
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+chmod +x "$HOOK"
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+
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+echo dummy template > "$(git rev-parse --git-dir)/template"
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+
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+test_expect_success 'with hook (-m)' '
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+
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+ echo "more" >> file &&
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+ git add file &&
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+ git commit -m "more" &&
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+ test "`git log -1 --pretty=format:%s`" = "message (no editor)"
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+
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+'
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+
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+test_expect_success 'with hook (-m editor)' '
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+
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+ echo "more" >> file &&
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+ git add file &&
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+ GIT_EDITOR="$FAKE_EDITOR" git commit -e -m "more more" &&
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+ test "`git log -1 --pretty=format:%s`" = message
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+
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+'
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+
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+test_expect_success 'with hook (-t)' '
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+
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+ echo "more" >> file &&
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+ git add file &&
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+ git commit -t "$(git rev-parse --git-dir)/template" &&
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+ test "`git log -1 --pretty=format:%s`" = template
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+
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+'
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+
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+test_expect_success 'with hook (-F)' '
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+
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+ echo "more" >> file &&
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+ git add file &&
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+ (echo more | git commit -F -) &&
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+ test "`git log -1 --pretty=format:%s`" = "message (no editor)"
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+
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+'
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+
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+test_expect_success 'with hook (-F editor)' '
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+
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+ echo "more" >> file &&
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+ git add file &&
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+ (echo more more | GIT_EDITOR="$FAKE_EDITOR" git commit -e -F -) &&
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+ test "`git log -1 --pretty=format:%s`" = message
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+
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+'
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+
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+test_expect_success 'with hook (-C)' '
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+
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+ head=`git rev-parse HEAD` &&
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+ echo "more" >> file &&
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+ git add file &&
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+ git commit -C $head &&
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+ test "`git log -1 --pretty=format:%s`" = "$head (no editor)"
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+
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+'
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+
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+test_expect_success 'with hook (editor)' '
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+
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+ echo "more more" >> file &&
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+ git add file &&
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+ GIT_EDITOR="$FAKE_EDITOR" git commit &&
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+ test "`git log -1 --pretty=format:%s`" = default
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+
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+'
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+
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+test_expect_success 'with hook (--amend)' '
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+
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+ head=`git rev-parse HEAD` &&
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+ echo "more" >> file &&
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+ git add file &&
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+ GIT_EDITOR="$FAKE_EDITOR" git commit --amend &&
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+ test "`git log -1 --pretty=format:%s`" = "$head"
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+
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+'
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+
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+test_expect_success 'with hook (-c)' '
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+
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+ head=`git rev-parse HEAD` &&
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+ echo "more" >> file &&
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+ git add file &&
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+ GIT_EDITOR="$FAKE_EDITOR" git commit -c $head &&
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+ test "`git log -1 --pretty=format:%s`" = "$head"
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+
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+'
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+
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+cat > "$HOOK" <<'EOF'
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+#!/bin/sh
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+exit 1
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+EOF
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+
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+test_expect_success 'with failing hook' '
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+
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+ head=`git rev-parse HEAD` &&
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+ echo "more" >> file &&
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+ git add file &&
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+ ! GIT_EDITOR="$FAKE_EDITOR" git commit -c $head
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+
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+'
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+
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+test_expect_success 'with failing hook (--no-verify)' '
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+
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+ head=`git rev-parse HEAD` &&
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+ echo "more" >> file &&
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+ git add file &&
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+ ! GIT_EDITOR="$FAKE_EDITOR" git commit --no-verify -c $head
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+
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+'
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+
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+
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+test_done
templates/hooks--commit-msg
+3
@@ -9,6 +9,9 @@
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# To enable this hook, make this file executable.
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# Uncomment the below to add a Signed-off-by line to the message.
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+# Doing this in a hook is a bad idea in general, but the prepare-commit-msg
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+# hook is more suited to it.
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+#
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# SOB=$(git var GIT_AUTHOR_IDENT | sed -n 's/^\(.*>\).*$/Signed-off-by: \1/p')
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# grep -qs "^$SOB" "$1" || echo "$SOB" >> "$1"
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templates/hooks--prepare-commit-msg
new
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@@ -0,0 +1,36 @@
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+#!/bin/sh
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+#
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+# An example hook script to prepare the commit log message.
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+# Called by git-commit with the name of the file that has the
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+# commit message, followed by the description of the commit
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+# message's source. The hook's purpose is to edit the commit
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+# message file. If the hook fails with a non-zero status,
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+# the commit is aborted.
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+#
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+# To enable this hook, make this file executable.
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+
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+# This hook includes three examples. The first comments out the
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+# "Conflicts:" part of a merge commit.
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+#
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+# The second includes the output of "git diff --name-status -r"
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+# into the message, just before the "git status" output. It is
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+# commented because it doesn't cope with --amend or with squashed
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+# commits.
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+#
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+# The third example adds a Signed-off-by line to the message, that can
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+# still be edited. This is rarely a good idea.
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+
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+case "$2 $3" in
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+ merge)
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+ sed -i '/^Conflicts:/,/#/!b;s/^/# &/;s/^# #/#/' "$1" ;;
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+
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+# ""|template)
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+# perl -i -pe '
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+# print "\n" . `git diff --cached --name-status -r`
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+# if /^#/ && $first++ == 0' "$1" ;;
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+
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+ *) ;;
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+esac
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+
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+# SOB=$(git var GIT_AUTHOR_IDENT | sed -n 's/^\(.*>\).*$/Signed-off-by: \1/p')
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+# grep -qs "^$SOB" "$1" || echo "$SOB" >> "$1"