From cf10f9fdd5e673a163847f0e931ce9731507e03b Mon Sep 17 00:00:00 2001 From: Miklos Vajna Date: Fri, 3 Oct 2008 14:04:47 +0200 Subject: builtin-commit: use reduce_heads() only when appropriate MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since commit 6bb6b034 (builtin-commit: use commit_tree(), 2008-09-10), builtin-commit performs a reduce_heads() unconditionally. However, it's not always needed, and in some cases even harmful. reduce_heads() is not needed for the initial commit or for an "ordinary" commit, because they don't have any or have only one parent, respectively. reduce_heads() must be avoided when 'git commit' is run after a 'git merge --no-ff --no-commit', otherwise it will turn the non-fast-forward merge into fast-forward. For the same reason, reduce_heads() must be avoided when amending such a merge commit. To resolve this issue, 'git merge' will write info about whether fast-forward is allowed or not to $GIT_DIR/MERGE_MODE. Based on this info, 'git commit' will only perform reduce_heads() when it's committing a merge and fast-forward is enabled. Also add test cases to ensure that non-fast-forward merges are committed and amended properly. Signed-off-by: Miklos Vajna Signed-off-by: SZEDER Gábor Signed-off-by: Shawn O. Pearce --- builtin-commit.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'builtin-commit.c') diff --git a/builtin-commit.c b/builtin-commit.c index b92025752..93f360f76 100644 --- a/builtin-commit.c +++ b/builtin-commit.c @@ -937,6 +937,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix) unsigned char commit_sha1[20]; struct ref_lock *ref_lock; struct commit_list *parents = NULL, **pptr = &parents; + struct stat statbuf; + int allow_fast_forward = 1; git_config(git_commit_config, NULL); @@ -951,6 +953,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix) return 1; } + strbuf_init(&sb, 0); /* Determine parents */ if (initial_commit) { reflog_msg = "commit (initial)"; @@ -984,14 +987,22 @@ int cmd_commit(int argc, const char **argv, const char *prefix) } fclose(fp); strbuf_release(&m); + if (!stat(git_path("MERGE_MODE"), &statbuf)) { + if (strbuf_read_file(&sb, git_path("MERGE_MODE"), 0) < 0) + die("could not read MERGE_MODE: %s", + strerror(errno)); + if (!strcmp(sb.buf, "no-ff")) + allow_fast_forward = 0; + } + if (allow_fast_forward) + parents = reduce_heads(parents); } else { reflog_msg = "commit"; pptr = &commit_list_insert(lookup_commit(head_sha1), pptr)->next; } - parents = reduce_heads(parents); /* Finally, get the commit message */ - strbuf_init(&sb, 0); + strbuf_reset(&sb); if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) { rollback_index_files(); die("could not read commit message"); @@ -1040,6 +1051,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix) unlink(git_path("MERGE_HEAD")); unlink(git_path("MERGE_MSG")); + unlink(git_path("MERGE_MODE")); unlink(git_path("SQUASH_MSG")); if (commit_index_files()) -- cgit v1.2.1