+ if (!commitable && !in_merge && !allow_empty &&
+ !(amend && is_a_merge(head_sha1))) {
+ run_status(stdout, index_file, prefix, 0);
+ unlink(commit_editmsg);
+ return 0;
+ }
+
+ /*
+ * Re-read the index as pre-commit hook could have updated it,
+ * and write it out as a tree. We must do this before we invoke
+ * the editor and after we invoke run_status above.
+ */
+ discard_cache();
+ read_cache_from(index_file);
+ if (!active_cache_tree)
+ active_cache_tree = cache_tree();
+ if (cache_tree_update(active_cache_tree,
+ active_cache, active_nr, 0, 0) < 0) {
+ error("Error building trees");
+ 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 };
+ snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
+ launch_editor(git_path(commit_editmsg), NULL, env);
+ }
+
+ if (!no_verify &&
+ run_hook(index_file, "commit-msg", git_path(commit_editmsg), NULL)) {
+ return 0;
+ }
+
+ return 1;