Re: [PATCH 28/48] merge-recursive: Split update_stages_and_entry; only update stages at end

[Junio C Hamano <gitster@pobox.com>]

Elijah Newren <newren@gmail.com> writes:

> Instead of having the process_renames logic update the stages in the index
> for the rename destination, have the index updated after process_entry or
> process_df_entry.  This will also allow us to have process_entry determine
> whether a file was tracked and existed in the working copy before the
> merge started.
>
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
>  merge-recursive.c |   35 +++++++++++++++++------------------
>  1 files changed, 17 insertions(+), 18 deletions(-)
>
> diff --git a/merge-recursive.c b/merge-recursive.c
> index b4baa35..7878b30 100644
> --- a/merge-recursive.c
> +++ b/merge-recursive.c
> @@ -90,6 +90,7 @@ struct stage_data {
>  	} stages[4];
>  	struct rename_df_conflict_info *rename_df_conflict_info;
>  	unsigned processed:1;
> +	unsigned involved_in_rename:1;
>  };
>  
>  static inline void setup_rename_df_conflict_info(enum rename_type rename_type,
> @@ -516,15 +517,11 @@ static int update_stages(const char *path, const struct diff_filespec *o,
>  	return 0;
>  }
>  
> -static int update_stages_and_entry(const char *path,
> -				   struct stage_data *entry,
> -				   struct diff_filespec *o,
> -				   struct diff_filespec *a,
> -				   struct diff_filespec *b,
> -				   int clear)
> +static void update_entry(struct stage_data *entry,
> +			 struct diff_filespec *o,
> +			 struct diff_filespec *a,
> +			 struct diff_filespec *b)
>  {
> -	int options;
> -
>  	entry->processed = 0;
>  	entry->stages[1].mode = o->mode;
>  	entry->stages[2].mode = a->mode;
> @@ -532,7 +529,6 @@ static int update_stages_and_entry(const char *path,
>  	hashcpy(entry->stages[1].sha, o->sha1);
>  	hashcpy(entry->stages[2].sha, a->sha1);
>  	hashcpy(entry->stages[3].sha, b->sha1);
> -	return update_stages(path, o, a, b);
>  }
>  
>  static int remove_file(struct merge_options *o, int clean,
> @@ -1084,12 +1080,11 @@ static int process_renames(struct merge_options *o,
>  							      ren2->dst_entry);
>  			} else {
>  				remove_file(o, 1, ren1_src, 1);

Hopefully this unconditional removal from the working tree will be fixed
by the end of the series, at least for the virtual ancestor merges.

> -				update_stages_and_entry(ren1_dst,
> -							ren1->dst_entry,
> -							ren1->pair->one,
> -							ren1->pair->two,
> -							ren2->pair->two,
> -							1 /* clear */);
> +				update_entry(ren1->dst_entry,
> +					     ren1->pair->one,
> +					     ren1->pair->two,
> +					     ren2->pair->two);
> +				ren1->dst_entry->involved_in_rename = 1;

So the idea is to just record what the stage data should be, and delay
calling update_stages() until we run the content level merge?

> @@ -1291,6 +1287,7 @@ static void handle_delete_modify(struct merge_options *o,
>  }
>  
>  static int merge_content(struct merge_options *o,
> +			 unsigned involved_in_rename,
>  			 const char *path,
>  			 unsigned char *o_sha, int o_mode,
>  			 unsigned char *a_sha, int a_mode,
> @@ -1331,6 +1328,8 @@ static int merge_content(struct merge_options *o,
>  			reason = "submodule";
>  		output(o, 1, "CONFLICT (%s): Merge conflict in %s",
>  				reason, path);
> +		if (involved_in_rename)
> +			update_stages(path, &one, &a, &b);
>  	}
>  
>  	if (df_conflict_remains) {
> @@ -1415,7 +1414,7 @@ static int process_entry(struct merge_options *o,
>  	} else if (a_sha && b_sha) {
>  		/* Case C: Added in both (check for same permissions) and */
>  		/* case D: Modified in both, but differently. */
> -		clean_merge = merge_content(o, path,
> +		clean_merge = merge_content(o, entry->involved_in_rename, path,
>  					    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
>  					    NULL);
>  	} else if (!o_sha && !a_sha && !b_sha) {
> @@ -1459,7 +1458,7 @@ static int process_df_entry(struct merge_options *o,
>  		char *src;
>  		switch (conflict_info->rename_type) {
>  		case RENAME_NORMAL:
> -			clean_merge = merge_content(o, path,
> +			clean_merge = merge_content(o, entry->involved_in_rename, path,
>  						    o_sha, o_mode, a_sha, a_mode, b_sha, b_mode,
>  						    conflict_info->branch1);
>  			break;

Feels sane from a cursory look, but are there cases where we do update_entry()
above and end up not calling merge_content() at all?