]> asedeno.scripts.mit.edu Git - git.git/blobdiff - builtin-commit.c
git-commit: Allow to amend a merge commit that does not change the tree
[git.git] / builtin-commit.c
index 2233300f40f8312adc4494fb7fc488d7c6617048..6c2dc390c451d5942521ddef9f046c5f98097dc3 100644 (file)
@@ -7,6 +7,7 @@
 
 #include "cache.h"
 #include "cache-tree.h"
+#include "dir.h"
 #include "builtin.h"
 #include "diff.h"
 #include "diffcore.h"
 #include "strbuf.h"
 #include "utf8.h"
 #include "parse-options.h"
+#include "path-list.h"
 
 static const char * const builtin_commit_usage[] = {
        "git-commit [options] [--] <filepattern>...",
        NULL
 };
 
+static const char * const builtin_status_usage[] = {
+       "git-status [options] [--] <filepattern>...",
+       NULL
+};
+
 static unsigned char head_sha1[20], merge_head_sha1[20];
 static char *use_message_buffer;
 static const char commit_editmsg[] = "COMMIT_EDITMSG";
-static struct lock_file lock_file;
+static struct lock_file index_lock; /* real index */
+static struct lock_file false_lock; /* used only for partial commits */
+static enum {
+       COMMIT_AS_IS = 1,
+       COMMIT_NORMAL,
+       COMMIT_PARTIAL,
+} commit_style;
 
 static char *logfile, *force_author, *template_file;
 static char *edit_message, *use_message;
@@ -78,40 +91,179 @@ static struct option builtin_commit_options[] = {
        OPT_END()
 };
 
+static void rollback_index_files(void)
+{
+       switch (commit_style) {
+       case COMMIT_AS_IS:
+               break; /* nothing to do */
+       case COMMIT_NORMAL:
+               rollback_lock_file(&index_lock);
+               break;
+       case COMMIT_PARTIAL:
+               rollback_lock_file(&index_lock);
+               rollback_lock_file(&false_lock);
+               break;
+       }
+}
+
+static void commit_index_files(void)
+{
+       switch (commit_style) {
+       case COMMIT_AS_IS:
+               break; /* nothing to do */
+       case COMMIT_NORMAL:
+               commit_lock_file(&index_lock);
+               break;
+       case COMMIT_PARTIAL:
+               commit_lock_file(&index_lock);
+               rollback_lock_file(&false_lock);
+               break;
+       }
+}
+
+/*
+ * Take a union of paths in the index and the named tree (typically, "HEAD"),
+ * and return the paths that match the given pattern in list.
+ */
+static int list_paths(struct path_list *list, const char *with_tree,
+                     const char *prefix, const char **pattern)
+{
+       int i;
+       char *m;
+
+       for (i = 0; pattern[i]; i++)
+               ;
+       m = xcalloc(1, i);
+
+       if (with_tree)
+               overlay_tree_on_cache(with_tree, prefix);
+
+       for (i = 0; i < active_nr; i++) {
+               struct cache_entry *ce = active_cache[i];
+               if (ce->ce_flags & htons(CE_UPDATE))
+                       continue;
+               if (!pathspec_match(pattern, m, ce->name, 0))
+                       continue;
+               path_list_insert(ce->name, list);
+       }
+
+       return report_path_error(m, pattern, prefix ? strlen(prefix) : 0);
+}
+
+static void add_remove_files(struct path_list *list)
+{
+       int i;
+       for (i = 0; i < list->nr; i++) {
+               struct path_list_item *p = &(list->items[i]);
+               if (file_exists(p->path))
+                       add_file_to_cache(p->path, 0);
+               else
+                       remove_file_from_cache(p->path);
+       }
+}
+
 static char *prepare_index(const char **files, const char *prefix)
 {
        int fd;
        struct tree *tree;
-       struct lock_file *next_index_lock;
+       struct path_list partial;
+       const char **pathspec = NULL;
 
        if (interactive) {
                interactive_add();
+               commit_style = COMMIT_AS_IS;
                return get_index_file();
        }
 
-       fd = hold_locked_index(&lock_file, 1);
        if (read_cache() < 0)
                die("index file corrupt");
 
-       if (all || also) {
-               add_files_to_cache(verbose, also ? prefix : NULL, files);
+       if (*files)
+               pathspec = get_pathspec(prefix, files);
+
+       /*
+        * Non partial, non as-is commit.
+        *
+        * (1) get the real index;
+        * (2) update the_index as necessary;
+        * (3) write the_index out to the real index (still locked);
+        * (4) return the name of the locked index file.
+        *
+        * The caller should run hooks on the locked real index, and
+        * (A) if all goes well, commit the real index;
+        * (B) on failure, rollback the real index.
+        */
+       if (all || (also && pathspec && *pathspec)) {
+               int fd = hold_locked_index(&index_lock, 1);
+               add_files_to_cache(0, also ? prefix : NULL, pathspec);
                refresh_cache(REFRESH_QUIET);
                if (write_cache(fd, active_cache, active_nr) || close(fd))
                        die("unable to write new_index file");
-               return lock_file.filename;
+               commit_style = COMMIT_NORMAL;
+               return index_lock.filename;
        }
 
-       if (*files == NULL) {
-               /* Commit index as-is. */
-               rollback_lock_file(&lock_file);
+       /*
+        * As-is commit.
+        *
+        * (1) return the name of the real index file.
+        *
+        * The caller should run hooks on the real index, and run
+        * hooks on the real index, and create commit from the_index.
+        * We still need to refresh the index here.
+        */
+       if (!pathspec || !*pathspec) {
+               fd = hold_locked_index(&index_lock, 1);
+               refresh_cache(REFRESH_QUIET);
+               if (write_cache(fd, active_cache, active_nr) ||
+                   close(fd) || commit_locked_index(&index_lock))
+                       die("unable to write new_index file");
+               commit_style = COMMIT_AS_IS;
                return get_index_file();
        }
 
-       /* update the user index file */
-       add_files_to_cache(verbose, prefix, files);
+       /*
+        * A partial commit.
+        *
+        * (0) find the set of affected paths;
+        * (1) get lock on the real index file;
+        * (2) update the_index with the given paths;
+        * (3) write the_index out to the real index (still locked);
+        * (4) get lock on the false index file;
+        * (5) reset the_index from HEAD;
+        * (6) update the_index the same way as (2);
+        * (7) write the_index out to the false index file;
+        * (8) return the name of the false index file (still locked);
+        *
+        * The caller should run hooks on the locked false index, and
+        * create commit from it.  Then
+        * (A) if all goes well, commit the real index;
+        * (B) on failure, rollback the real index;
+        * In either case, rollback the false index.
+        */
+       commit_style = COMMIT_PARTIAL;
+
+       if (file_exists(git_path("MERGE_HEAD")))
+               die("cannot do a partial commit during a merge.");
+
+       memset(&partial, 0, sizeof(partial));
+       partial.strdup_paths = 1;
+       if (list_paths(&partial, initial_commit ? NULL : "HEAD", prefix, pathspec))
+               exit(1);
+
+       discard_cache();
+       if (read_cache() < 0)
+               die("cannot read the index");
+
+       fd = hold_locked_index(&index_lock, 1);
+       add_remove_files(&partial);
+       refresh_cache(REFRESH_QUIET);
        if (write_cache(fd, active_cache, active_nr) || close(fd))
                die("unable to write new_index file");
 
+       fd = hold_lock_file_for_update(&false_lock,
+                                      git_path("next-index-%d", getpid()), 1);
+       discard_cache();
        if (!initial_commit) {
                tree = parse_tree_indirect(head_sha1);
                if (!tree)
@@ -119,17 +271,12 @@ static char *prepare_index(const char **files, const char *prefix)
                if (read_tree(tree, 0, NULL))
                        die("failed to read HEAD tree object");
        }
-
-       /* Use a lock file to garbage collect the temporary index file. */
-       next_index_lock = xmalloc(sizeof(*next_index_lock));
-       fd = hold_lock_file_for_update(next_index_lock,
-                                      git_path("next-index-%d", getpid()), 1);
-       add_files_to_cache(verbose, prefix, files);
+       add_remove_files(&partial);
        refresh_cache(REFRESH_QUIET);
-       if (write_cache(fd, active_cache, active_nr) || close(fd))
-               die("unable to write new_index file");
 
-       return next_index_lock->filename;
+       if (write_cache(fd, active_cache, active_nr) || close(fd))
+               die("unable to write temporary index file");
+       return false_lock.filename;
 }
 
 static int run_status(FILE *fp, const char *index_file, const char *prefix)
@@ -158,7 +305,7 @@ static const char sign_off_header[] = "Signed-off-by: ";
 static int prepare_log_message(const char *index_file, const char *prefix)
 {
        struct stat statbuf;
-       int commitable;
+       int commitable, saved_color_setting;
        struct strbuf sb;
        char *buffer;
        FILE *fp;
@@ -194,7 +341,7 @@ static int prepare_log_message(const char *index_file, const char *prefix)
 
        fp = fopen(git_path(commit_editmsg), "w");
        if (fp == NULL)
-               die("could not open %s\n", git_path(commit_editmsg));
+               die("could not open %s", git_path(commit_editmsg));
 
        stripspace(&sb, 0);
 
@@ -204,11 +351,9 @@ static int prepare_log_message(const char *index_file, const char *prefix)
 
                strbuf_init(&sob, 0);
                strbuf_addstr(&sob, sign_off_header);
-               strbuf_addstr(&sob, fmt_ident(getenv("GIT_COMMITTER_NAME"),
-                                             getenv("GIT_COMMITTER_EMAIL"),
-                                             "", 1));
+               strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
+                                            getenv("GIT_COMMITTER_EMAIL")));
                strbuf_addch(&sob, '\n');
-
                for (i = sb.len - 1; i > 0 && sb.buf[i - 1] != '\n'; i--)
                        ; /* do nothing */
                if (prefixcmp(sb.buf + i, sob.buf)) {
@@ -220,11 +365,32 @@ static int prepare_log_message(const char *index_file, const char *prefix)
        }
 
        if (fwrite(sb.buf, 1, sb.len, fp) < sb.len)
-               die("could not write commit template: %s\n",
-                   strerror(errno));
+               die("could not write commit template: %s", strerror(errno));
 
        strbuf_release(&sb);
 
+       if (no_edit) {
+               struct rev_info rev;
+               unsigned char sha1[40];
+
+               fclose(fp);
+
+               if (!active_nr && read_cache() < 0)
+                       die("Cannot read index");
+
+               if (get_sha1("HEAD", sha1) != 0)
+                       return !!active_nr;
+
+               init_revisions(&rev, "");
+               rev.abbrev = 0;
+               setup_revisions(0, NULL, &rev, "HEAD");
+               DIFF_OPT_SET(&rev.diffopt, QUIET);
+               DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
+               run_diff_index(&rev, 1 /* cached */);
+
+               return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
+       }
+
        if (in_merge && !no_edit)
                fprintf(fp,
                        "#\n"
@@ -242,7 +408,10 @@ static int prepare_log_message(const char *index_file, const char *prefix)
        if (only_include_assumed)
                fprintf(fp, "# %s\n", only_include_assumed);
 
+       saved_color_setting = wt_status_use_color;
+       wt_status_use_color = 0;
        commitable = run_status(fp, index_file, prefix);
+       wt_status_use_color = saved_color_setting;
 
        fclose(fp);
 
@@ -303,13 +472,13 @@ static void determine_author_info(struct strbuf *sb)
 
                a = strstr(use_message_buffer, "\nauthor ");
                if (!a)
-                       die("invalid commit: %s\n", use_message);
+                       die("invalid commit: %s", use_message);
 
                lb = strstr(a + 8, " <");
                rb = strstr(a + 8, "> ");
                eol = strchr(a + 8, '\n');
                if (!lb || !rb || !eol)
-                       die("invalid commit: %s\n", use_message);
+                       die("invalid commit: %s", use_message);
 
                name = xstrndup(a + 8, lb - (a + 8));
                email = xstrndup(lb + 2, rb - (lb + 2));
@@ -321,7 +490,7 @@ static void determine_author_info(struct strbuf *sb)
                const char *rb = strchr(force_author, '>');
 
                if (!lb || !rb)
-                       die("malformed --author parameter\n");
+                       die("malformed --author parameter");
                name = xstrndup(force_author, lb - force_author);
                email = xstrndup(lb + 2, rb - (lb + 2));
        }
@@ -329,12 +498,12 @@ static void determine_author_info(struct strbuf *sb)
        strbuf_addf(sb, "author %s\n", fmt_ident(name, email, date, 1));
 }
 
-static int parse_and_validate_options(int argc, const char *argv[])
+static int parse_and_validate_options(int argc, const char *argv[],
+                                     const char * const usage[])
 {
        int f = 0;
 
-       argc = parse_options(argc, argv, builtin_commit_options,
-                            builtin_commit_usage, 0);
+       argc = parse_options(argc, argv, builtin_commit_options, usage, 0);
 
        if (logfile || message.len || use_message)
                no_edit = 1;
@@ -351,7 +520,7 @@ static int parse_and_validate_options(int argc, const char *argv[])
        if (amend && initial_commit)
                die("You have nothing to amend.");
        if (amend && in_merge)
-               die("You are in the middle of a merger -- cannot amend.");
+               die("You are in the middle of a merge -- cannot amend.");
 
        if (use_message)
                f++;
@@ -431,13 +600,13 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 
        git_config(git_status_config);
 
-       argc = parse_and_validate_options(argc, argv);
+       argc = parse_and_validate_options(argc, argv, builtin_status_usage);
 
        index_file = prepare_index(argv, prefix);
 
        commitable = run_status(stdout, index_file, prefix);
 
-       rollback_lock_file(&lock_file);
+       rollback_index_files();
 
        return commitable ? 0 : 1;
 }
@@ -474,7 +643,7 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 
        commit = lookup_commit(sha1);
        if (!commit)
-               die("couldn't look up newly created commit\n");
+               die("couldn't look up newly created commit");
        if (!commit || parse_commit(commit))
                die("could not parse newly created commit");
 
@@ -507,6 +676,14 @@ int git_commit_config(const char *k, const char *v)
        return git_status_config(k, v);
 }
 
+static int is_a_merge(const unsigned char *sha1)
+{
+       struct commit *commit = lookup_commit(sha1);
+       if (!commit || parse_commit(commit))
+               die("could not parse HEAD commit");
+       return !!(commit->parents && commit->parents->next);
+}
+
 static const char commit_utf8_warn[] =
 "Warning: commit message does not conform to UTF-8.\n"
 "You may want to amend it after fixing the message, or set the config\n"
@@ -514,43 +691,56 @@ static const char commit_utf8_warn[] =
 
 int cmd_commit(int argc, const char **argv, const char *prefix)
 {
-       int header_len, parent_count = 0;
+       int header_len;
        struct strbuf sb;
        const char *index_file, *reflog_msg;
-       char *nl;
+       char *nl, *p;
        unsigned char commit_sha1[20];
        struct ref_lock *ref_lock;
 
        git_config(git_commit_config);
 
-       argc = parse_and_validate_options(argc, argv);
+       argc = parse_and_validate_options(argc, argv, builtin_commit_usage);
 
        index_file = prepare_index(argv, prefix);
 
-       if (!no_verify && run_hook(index_file, "pre-commit", NULL))
-               exit(1);
+       if (!no_verify && run_hook(index_file, "pre-commit", NULL)) {
+               rollback_index_files();
+               return 1;
+       }
 
-       if (!prepare_log_message(index_file, prefix) && !in_merge) {
+       if (!prepare_log_message(index_file, prefix) && !in_merge &&
+           !(amend && is_a_merge(head_sha1))) {
                run_status(stdout, index_file, prefix);
+               rollback_index_files();
                unlink(commit_editmsg);
                return 1;
        }
 
-       strbuf_init(&sb, 0);
-
-       /* Start building up the commit header */
+       /*
+        * Re-read the index as pre-commit hook could have updated it,
+        * and write it out as a tree.
+        */
+       discard_cache();
        read_cache_from(index_file);
-       active_cache_tree = cache_tree();
+       if (!active_cache_tree)
+               active_cache_tree = cache_tree();
        if (cache_tree_update(active_cache_tree,
-                             active_cache, active_nr, 0, 0) < 0)
+                             active_cache, active_nr, 0, 0) < 0) {
+               rollback_index_files();
                die("Error building trees");
+       }
+
+       /*
+        * The commit object
+        */
+       strbuf_init(&sb, 0);
        strbuf_addf(&sb, "tree %s\n",
                    sha1_to_hex(active_cache_tree->sha1));
 
        /* Determine parents */
        if (initial_commit) {
                reflog_msg = "commit (initial)";
-               parent_count = 0;
        } else if (amend) {
                struct commit_list *c;
                struct commit *commit;
@@ -592,22 +782,37 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
        /* Get the commit message and validate it */
        header_len = sb.len;
        if (!no_edit) {
-               fprintf(stderr, "launching editor, log %s\n", logfile);
-               launch_editor(git_path(commit_editmsg), &sb);
-       } else if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0)
-               die("could not read commit message\n");
-       if (run_hook(index_file, "commit-msg", commit_editmsg))
+               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), &sb, env);
+       } else if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
+               rollback_index_files();
+               die("could not read commit message");
+       }
+       if (run_hook(index_file, "commit-msg", git_path(commit_editmsg))) {
+               rollback_index_files();
                exit(1);
+       }
+
+       /* Truncate the message just before the diff, if any. */
+       p = strstr(sb.buf, "\ndiff --git a/");
+       if (p != NULL)
+               strbuf_setlen(&sb, p - sb.buf + 1);
+
        stripspace(&sb, 1);
-       if (sb.len < header_len ||
-           message_is_empty(&sb, header_len))
-               die("* no commit message?  aborting commit.");
+       if (sb.len < header_len || message_is_empty(&sb, header_len)) {
+               rollback_index_files();
+               die("no commit message?  aborting commit.");
+       }
        strbuf_addch(&sb, '\0');
        if (is_encoding_utf8(git_commit_encoding) && !is_utf8(sb.buf))
                fprintf(stderr, commit_utf8_warn);
 
-       if (write_sha1_file(sb.buf, sb.len - 1, commit_type, commit_sha1))
+       if (write_sha1_file(sb.buf, sb.len - 1, commit_type, commit_sha1)) {
+               rollback_index_files();
                die("failed to write commit object");
+       }
 
        ref_lock = lock_any_ref_for_update("HEAD",
                                           initial_commit ? NULL : head_sha1,
@@ -622,21 +827,22 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
        strbuf_insert(&sb, 0, reflog_msg, strlen(reflog_msg));
        strbuf_insert(&sb, strlen(reflog_msg), ": ", 2);
 
-       if (!ref_lock)
+       if (!ref_lock) {
+               rollback_index_files();
                die("cannot lock HEAD ref");
-       if (write_ref_sha1(ref_lock, commit_sha1, sb.buf) < 0)
+       }
+       if (write_ref_sha1(ref_lock, commit_sha1, sb.buf) < 0) {
+               rollback_index_files();
                die("cannot update HEAD ref");
+       }
 
        unlink(git_path("MERGE_HEAD"));
        unlink(git_path("MERGE_MSG"));
 
-       if (lock_file.filename[0] && commit_locked_index(&lock_file))
-               die("failed to write new index");
+       commit_index_files();
 
        rerere();
-
-       run_hook(index_file, "post-commit", NULL);
-
+       run_hook(get_index_file(), "post-commit", NULL);
        if (!quiet)
                print_summary(prefix, commit_sha1);