Re: [PATCH 09/12] merge-tree: provide a list of which files have conflicts

> From: Elijah Newren <newren@gmail.com>
>
> Callers of `git merge-tree --write-tree` will often want to know which
> files had conflicts.  While they could potentially attempt to parse the
> CONFLICT notices printed, those messages are not meant to be machine
> readable.  Provide a simpler mechanism of just printing the files (in
> the same format as `git ls-files` with quoting, but restricted to
> unmerged files) in the output before the free-form messages.
>
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
>  Documentation/git-merge-tree.txt |  8 ++++++++
>  builtin/merge-tree.c             | 24 ++++++++++++++++++++++--
>  t/t4301-merge-tree-real.sh       | 11 +++++++++++
>  3 files changed, 41 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt
> index fd7a867de60..041a4ac2785 100644
> --- a/Documentation/git-merge-tree.txt
> +++ b/Documentation/git-merge-tree.txt
> @@ -58,6 +58,7 @@ simply one line:
>  Whereas for a conflicted merge, the output is by default of the form:
>
>  	<OID of toplevel tree>
> +	<Conflicted file list>
>  	<Informational messages>

>
>  These are discussed individually below.
> @@ -69,6 +70,13 @@ This is a tree object that represents what would be checked out in the
>  working tree at the end of `git merge`.  If there were conflicts, then
>  files within this tree may have embedded conflict markers.
>
> +Conflicted file list
> +~~~~~~~~~~~~~~~~~~~~
> +
> +This is a sequence of lines containing a filename on each line, quoted
> +as explained for the configuration variable `core.quotePath` (see
> +linkgit:git-config[1]).
> +
>  Informational messages
>  ~~~~~~~~~~~~~~~~~~~~~~
>
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 560640ad911..d8eeeb3f306 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -11,6 +11,9 @@
>  #include "blob.h"
>  #include "exec-cmd.h"
>  #include "merge-blobs.h"
> +#include "quote.h"
> +
> +static int line_termination = '\n';
>
>  struct merge_list {
>  	struct merge_list *next;
> @@ -395,7 +398,8 @@ struct merge_tree_options {
>  };
>
>  static int real_merge(struct merge_tree_options *o,
> -		      const char *branch1, const char *branch2)
> +		      const char *branch1, const char *branch2,
> +		      const char *prefix)
>  {
>  	struct commit *parent1, *parent2;
>  	struct commit_list *common;
> @@ -449,6 +453,22 @@ static int real_merge(struct merge_tree_options *o,
>  		o->show_messages = !result.clean;
>
>  	printf("%s\n", oid_to_hex(&result.tree->object.oid));
> +	if (!result.clean) {
> +		struct string_list conflicted_files = STRING_LIST_INIT_NODUP;
> +		const char *last = NULL;
> +		int i;
> +
> +		merge_get_conflicted_files(&result, &conflicted_files);
> +		for (i = 0; i < conflicted_files.nr; i++) {
> +			const char *name = conflicted_files.items[i].string;
> +			if (last && !strcmp(last, name))
> +				continue;
> +			write_name_quoted_relative(
> +				name, prefix, stdout, line_termination);
> +			last = name;
> +		}
> +		string_list_clear(&conflicted_files, 1);
> +	}
>  	if (o->show_messages) {
>  		printf("\n");

>  		merge_display_update_messages(&opt, &result, stdout);
> @@ -502,7 +522,7 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>
>  	/* Do the relevant type of merge */
>  	if (o.real)
> -		return real_merge(&o, argv[0], argv[1]);
> +		return real_merge(&o, argv[0], argv[1], prefix);
>  	else
>  		return trivial_merge(argv[0], argv[1], argv[2]);
>  }
> diff --git a/t/t4301-merge-tree-real.sh b/t/t4301-merge-tree-real.sh
> index c34f8e6c1ed..43c9950dedb 100755
> --- a/t/t4301-merge-tree-real.sh
> +++ b/t/t4301-merge-tree-real.sh
> @@ -94,6 +94,8 @@ test_expect_success 'test conflict notices and such' '
>  	#   "whatever" has *both* a modify/delete and a file/directory conflict
>  	cat <<-EOF >expect &&
>  	HASH
> +	greeting
> +	whatever~side1
>
>  	Auto-merging greeting
>  	CONFLICT (content): Merge conflict in greeting

> @@ -105,4 +107,13 @@ test_expect_success 'test conflict notices and such' '
>  	test_cmp expect actual
>  '
>
> +test_expect_success 'Just the conflicted files without the messages' '
> +	test_expect_code 1 git merge-tree --write-tree --no-messages side1 side2 >out &&
> +	sed -e "s/[0-9a-f]\{40,\}/HASH/g" out >actual &&
> +
> +	test_write_lines HASH greeting whatever~side1 >expect &&
> +
> +	test_cmp expect actual
> +'
> +
>  test_done
> --
> gitgitgadget
>
>