From 172b6428d06ff4eb0812f087a497d50b6c878fe1 Mon Sep 17 00:00:00 2001 From: Clemens Buchacher Date: Sun, 14 Nov 2010 23:07:49 +0100 Subject: [PATCH] do not overwrite untracked during merge from unborn branch In case HEAD does not point to a valid commit yet, merge is implemented as a hard reset. This will cause untracked files to be overwritten. Instead, assume the empty tree for HEAD and do a regular merge. An untracked file will cause the merge to abort and do nothing. If no conflicting files are present, the merge will have the same effect as a hard reset. Signed-off-by: Clemens Buchacher Signed-off-by: Junio C Hamano --- builtin/merge.c | 20 +++++++++++++++++++- t/t7607-merge-overwrite.sh | 16 ++++++++++++++++ 2 files changed, 35 insertions(+), 1 deletion(-) diff --git a/builtin/merge.c b/builtin/merge.c index 37ce4f589f..2a6c49f6ce 100644 --- a/builtin/merge.c +++ b/builtin/merge.c @@ -231,6 +231,24 @@ static void save_state(void) die("not a valid object: %s", buffer.buf); } +static void read_empty(unsigned const char *sha1, int verbose) +{ + int i = 0; + const char *args[7]; + + args[i++] = "read-tree"; + if (verbose) + args[i++] = "-v"; + args[i++] = "-m"; + args[i++] = "-u"; + args[i++] = EMPTY_TREE_SHA1_HEX; + args[i++] = sha1_to_hex(sha1); + args[i] = NULL; + + if (run_command_v_opt(args, RUN_GIT_CMD)) + die("read-tree failed"); +} + static void reset_hard(unsigned const char *sha1, int verbose) { int i = 0; @@ -979,7 +997,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix) die("%s - not something we can merge", argv[0]); update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0, DIE_ON_ERR); - reset_hard(remote_head->sha1, 0); + read_empty(remote_head->sha1, 0); return 0; } else { struct strbuf merge_names = STRBUF_INIT; diff --git a/t/t7607-merge-overwrite.sh b/t/t7607-merge-overwrite.sh index 49f4e1599a..8317a574ce 100755 --- a/t/t7607-merge-overwrite.sh +++ b/t/t7607-merge-overwrite.sh @@ -84,4 +84,20 @@ test_expect_success 'will not overwrite removed file with staged changes' ' test_cmp important c1.c ' +cat >expect <<\EOF +error: Untracked working tree file 'c0.c' would be overwritten by merge. +fatal: read-tree failed +EOF + +test_expect_success 'will not overwrite untracked file on unborn branch' ' + git reset --hard c0 && + git rm -fr . && + git checkout --orphan new && + cp important c0.c && + test_must_fail git merge c0 2>out && + test_cmp out expect && + test_path_is_missing .git/MERGE_HEAD && + test_cmp important c0.c +' + test_done -- 2.11.4.GIT