[PATCH v2] git-mv: improve error message for conflicted file

From: Chris Torek <chris.torek@gmail.com>

'git mv' has always complained about renaming a conflicted file, as it cannot handle multiple index entries for one file. However, the error message it uses has been the same as the one for an untracked file:

    fatal: not under version control, src=...

which is patently wrong. Distinguish the two cases and add a test to make sure we produce the correct message.

Signed-off-by: Chris Torek <chris.torek@gmail.com>
---
    git-mv: improve error message for conflicted file
    
    'git mv' has always complained about renaming a conflicted file, as it
    cannot handle multiple index entries for one file. However, the error
    message it uses has been the same as the one for an untracked file:
    
    fatal: not under version control, src=...
    
    which is patently wrong. Distinguish the two cases and add a test to
    make sure we produce the correct message.
    
    Signed-off-by: Chris Torek chris.torek@gmail.com [chris.torek@gmail.com]
    
    
    ------------------------------------------------------------------------
    
    Tests updated, and took Junio's suggestion to reduce the cache lookup to
    one call.
    
    I put in the shortened "conflicted" here but did not shorten the
    existing "not under version control" message (to minimize the visible
    and translations-required changes).
    
    I like the idea of renaming all stages and keeping them at their current
    stages, but that's too much for this patch.
    
    I'll be traveling next week and not sure if I will get to any followups
    for a while.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-678%2Fchris3torek%2Fgit-mv-message-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-678/chris3torek/git-mv-message-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/678

Range-diff vs v1:

 1:  0b617e74f7 ! 1:  f2e251a7ea git-mv: improve error message for conflicted file
     @@ Commit message
          Signed-off-by: Chris Torek <chris.torek@gmail.com>
      
       ## builtin/mv.c ##
     +@@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
     + 	struct stat st;
     + 	struct string_list src_for_dst = STRING_LIST_INIT_NODUP;
     + 	struct lock_file lock_file = LOCK_INIT;
     ++	struct cache_entry *ce;
     + 
     + 	git_config(git_default_config, NULL);
     + 
      @@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
       				}
       				argc += last - first;
       			}
      -		} else if (cache_name_pos(src, length) < 0)
     --			bad = _("not under version control");
     ++		} else if (!(ce = cache_file_exists(src, length, ignore_case))) {
     + 			bad = _("not under version control");
      -		else if (lstat(dst, &st) == 0 &&
     -+		} else if (cache_name_pos(src, length) < 0) {
     -+			/*
     -+			 * This occurs for both untracked files *and*
     -+			 * files that are in merge-conflict state, so
     -+			 * let's distinguish between those two.
     -+			 */
     -+			struct cache_entry *ce = cache_file_exists(src, length, ignore_case);
     -+			if (ce == NULL)
     -+				bad = _("not under version control");
     -+			else
     -+				bad = _("must resolve merge conflict first");
     ++		} else if (ce_stage(ce)) {
     ++			bad = _("conflicted");
      +		} else if (lstat(dst, &st) == 0 &&
       			 (!ignore_case || strcasecmp(src, dst))) {
       			bad = _("destination exists");
     @@ t/t7001-mv.sh: test_expect_success 'git mv should not change sha1 of moved cache
      +test_expect_success 'git mv error on conflicted file' '
      +	rm -fr .git &&
      +	git init &&
     -+	touch conflicted &&
     -+	cfhash=$(git hash-object -w conflicted) &&
     -+	git update-index --index-info <<-EOF &&
     -+	$(printf "0 $cfhash 0\tconflicted\n")
     -+	$(printf "100644 $cfhash 1\tconflicted\n")
     ++	>conflict &&
     ++	test_when_finished "rm -f conflict" &&
     ++	cfhash=$(git hash-object -w conflict) &&
     ++	q_to_tab <<-EOF | git update-index --index-info &&
     ++	0 $cfhash 0Qconflict
     ++	100644 $cfhash 1Qconflict
      +	EOF
      +
     -+	test_must_fail git mv conflicted newname 2>actual &&
     -+	test_i18ngrep "merge.conflict" actual
     ++	test_must_fail git mv conflict newname 2>actual &&
     ++	test_i18ngrep "conflicted" actual
      +'
     -+
     -+rm -f conflicted
      +
       test_expect_success 'git mv should overwrite symlink to a file' '
       

 builtin/mv.c  |  7 +++++--
 t/t7001-mv.sh | 17 +++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)