git-commit: add a prepare-commit-msg hook

diff --git a/builtin-commit.c b/builtin-commit.c
index e8cb32059091ce0fdc693096617f08e93203e0e8..03caa30f0e4232bb613f70a04fa2914385e2cd6f 100644 (file)
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -394,6 +394,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
        struct strbuf sb;
        char *buffer;
        FILE *fp;
+       const char *hook_arg1 = NULL;
+       const char *hook_arg2 = NULL;
 
        if (!no_verify && run_hook(index_file, "pre-commit", NULL))
                return 0;
@@ -401,32 +403,47 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
        strbuf_init(&sb, 0);
        if (message.len) {
                strbuf_addbuf(&sb, &message);
+               hook_arg1 = "message";
        } else if (logfile && !strcmp(logfile, "-")) {
                if (isatty(0))
                        fprintf(stderr, "(reading log message from standard input)\n");
                if (strbuf_read(&sb, 0, 0) < 0)
                        die("could not read log from standard input");
+               hook_arg1 = "message";
        } else if (logfile) {
                if (strbuf_read_file(&sb, logfile, 0) < 0)
                        die("could not read log file '%s': %s",
                            logfile, strerror(errno));
+               hook_arg1 = "message";
        } else if (use_message) {
                buffer = strstr(use_message_buffer, "\n\n");
                if (!buffer || buffer[2] == '\0')
                        die("commit has empty message");
                strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
+               hook_arg1 = "commit";
+               hook_arg2 = use_message;
        } else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
                if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
                        die("could not read MERGE_MSG: %s", strerror(errno));
+               hook_arg1 = "merge";
        } else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
                if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
                        die("could not read SQUASH_MSG: %s", strerror(errno));
+               hook_arg1 = "squash";
        } else if (template_file && !stat(template_file, &statbuf)) {
                if (strbuf_read_file(&sb, template_file, 0) < 0)
                        die("could not read %s: %s",
                            template_file, strerror(errno));
+               hook_arg1 = "template";
        }
 
+       /*
+        * This final case does not modify the template message,
+        * it just sets the argument to the prepare-commit-msg hook.
+        */
+       else if (in_merge)
+               hook_arg1 = "merge";
+
        fp = fopen(git_path(commit_editmsg), "w");
        if (fp == NULL)
                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)
                return 0;
        }
 
+       if (run_hook(index_file, "prepare-commit-msg",
+                    git_path(commit_editmsg), hook_arg1, hook_arg2, NULL))
+               return 0;
+
        if (use_editor) {
                char index[PATH_MAX];
                const char *env[2] = { index, NULL };