[v2,10/11] merge-ort: add implementation of normal rename handling

Commit Message

Elijah Newren Dec. 14, 2020, 4:21 p.m. UTC

From: Elijah Newren <[e-mail]>

Implement handling of normal renames.  This code replaces the following
from merge-recurisve.c:

  * the code relevant to RENAME_NORMAL in process_renames()
  * the RENAME_NORMAL case of process_entry()

Also, there is some shared code from merge-recursive.c for multiple
different rename cases which we will no longer need for this case (or
other rename cases):

  * handle_rename_normal()
  * setup_rename_conflict_info()

The consolidation of four separate codepaths into one is made possible
by a change in design: process_renames() tweaks the conflict_info
entries within opt->priv->paths such that process_entry() can then
handle all the non-rename conflict types (directory/file, modify/delete,
etc.) orthogonally.  This means we're much less likely to miss special
implementation of some kind of combination of conflict types (see
commits brought in by 66c62eaec6 ("Merge branch 'en/merge-tests'",
2020-11-18), especially commit ef52778708 ("merge tests: expect improved
directory/file conflict handling in ort", 2020-10-26) for more details).
That, together with letting worktree/index updating be handled
orthogonally in the merge_switch_to_result() function, dramatically
simplifies the code for various special rename cases.

(To be fair, the code for handling normal renames wasn't all that
complicated beforehand, but it's still much simpler now.)

Signed-off-by: Elijah Newren <[e-mail]>
---
 merge-ort.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Derrick Stolee Dec. 15, 2020, 2:27 p.m. UTC | #1

On 12/14/2020 11:21 AM, Elijah Newren via GitGitGadget wrote:
> From: Elijah Newren <[e-mail]>
> 
> Implement handling of normal renames.  This code replaces the following
> from merge-recurisve.c:
> 
>   * the code relevant to RENAME_NORMAL in process_renames()
>   * the RENAME_NORMAL case of process_entry()
> 
> Also, there is some shared code from merge-recursive.c for multiple
> different rename cases which we will no longer need for this case (or
> other rename cases):
> 
>   * handle_rename_normal()
>   * setup_rename_conflict_info()
> 
> The consolidation of four separate codepaths into one is made possible
> by a change in design: process_renames() tweaks the conflict_info
> entries within opt->priv->paths such that process_entry() can then
> handle all the non-rename conflict types (directory/file, modify/delete,
> etc.) orthogonally.  This means we're much less likely to miss special
> implementation of some kind of combination of conflict types (see
> commits brought in by 66c62eaec6 ("Merge branch 'en/merge-tests'",
> 2020-11-18), especially commit ef52778708 ("merge tests: expect improved
> directory/file conflict handling in ort", 2020-10-26) for more details).
> That, together with letting worktree/index updating be handled
> orthogonally in the merge_switch_to_result() function, dramatically
> simplifies the code for various special rename cases.
> 
> (To be fair, the code for handling normal renames wasn't all that
> complicated beforehand, but it's still much simpler now.)

Definitely looks simple.

> +				memcpy(&newinfo->stages[other_source_index],
> +				       &oldinfo->stages[other_source_index],
> +				       sizeof(newinfo->stages[0]));
> +				newinfo->filemask |= (1 << other_source_index);
> +				newinfo->pathnames[other_source_index] = oldpath;

I'm happy your organization brought us to a clean place.

Thanks,
-Stolee

Patch

diff --git a/merge-ort.c b/merge-ort.c
index 4150ccc35e1..9aac33c8e31 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -869,7 +869,11 @@  static int process_renames(struct merge_options *opt,
 					 rename_branch, delete_branch);
 			} else {
 				/* normal rename */
-				die("Not yet implemented");
+				memcpy(&newinfo->stages[other_source_index],
+				       &oldinfo->stages[other_source_index],
+				       sizeof(newinfo->stages[0]));
+				newinfo->filemask |= (1 << other_source_index);
+				newinfo->pathnames[other_source_index] = oldpath;
 			}
 		}