Use information from previous blame parts (#28572) (#28577)

Backport #28572 by @KN4CK3R

Fixes #28545

`git blame` output can contain blocks without commit information if it
was outputted before (the `0dafa97ea3f6d9662299579e5be1875cd28baaae 48
26 1` line):
```
fec25436488499df7231f63b857f66457c193d5c 24 25 1
author Bastien Montagne
author-mail <bastien@blender.org>
author-time 1660731031
author-tz +0200
committer Bastien Montagne
committer-mail <bastien@blender.org>
committer-time 1660731031
committer-tz +0200
summary LibOverride: Add Make/Reset/Clear entries to IDTemplate contextual menu.
previous 839ece6477203382b7a7483062961540180ff1cd source/blender/editors/interface/interface_ops.c
filename source/blender/editors/interface/interface_ops.c
        #include "BLT_translation.h"
0dafa97ea3f6d9662299579e5be1875cd28baaae 48 26 1

3d57bc4397fca53bc9702a27bbf50102827829b0 27 27 1
author Hans Goudey
author-mail <hans@blender.org>
author-time 1700131315
author-tz +0100
committer Hans Goudey
committer-mail <hooglyboogly@noreply.localhost>
committer-time 1700131315
committer-tz +0100
summary Cleanup: Move several blenkernel headers to C++
previous 451c054d9b7d3148a646caa5a72fb127a5b5c408 source/blender/editors/interface/interface_ops.cc
filename source/blender/editors/interface/interface_ops.cc
        #include "BKE_context.hh"
```
This PR reuses data from the previous blame part to fill these gaps.

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

diff --git a/routers/web/repo/blame.go b/routers/web/repo/blame.go
index f07086ef1c854d5571b200fb4330633163680c29..a4ab2fc669c31755966893d7d6036c5d4222f039 100644 (file)
--- a/routers/web/repo/blame.go
+++ b/routers/web/repo/blame.go
@@ -125,7 +125,7 @@ func RefBlame(ctx *context.Context) {
 }
 
 type blameResult struct {
-       Parts                []git.BlamePart
+       Parts                []*git.BlamePart
        UsesIgnoreRevs       bool
        FaultyIgnoreRevsFile bool
 }
@@ -170,7 +170,9 @@ func performBlame(ctx *context.Context, repoPath string, commit *git.Commit, fil
 func fillBlameResult(br *git.BlameReader, r *blameResult) error {
        r.UsesIgnoreRevs = br.UsesIgnoreRevs()
 
-       r.Parts = make([]git.BlamePart, 0, 5)
+       previousHelper := make(map[string]*git.BlamePart)
+
+       r.Parts = make([]*git.BlamePart, 0, 5)
        for {
                blamePart, err := br.NextPart()
                if err != nil {
@@ -179,13 +181,23 @@ func fillBlameResult(br *git.BlameReader, r *blameResult) error {
                if blamePart == nil {
                        break
                }
-               r.Parts = append(r.Parts, *blamePart)
+
+               if prev, ok := previousHelper[blamePart.Sha]; ok {
+                       if blamePart.PreviousSha == "" {
+                               blamePart.PreviousSha = prev.PreviousSha
+                               blamePart.PreviousPath = prev.PreviousPath
+                       }
+               } else {
+                       previousHelper[blamePart.Sha] = blamePart
+               }
+
+               r.Parts = append(r.Parts, blamePart)
        }
 
        return nil
 }
 
-func processBlameParts(ctx *context.Context, blameParts []git.BlamePart) map[string]*user_model.UserCommit {
+func processBlameParts(ctx *context.Context, blameParts []*git.BlamePart) map[string]*user_model.UserCommit {
        // store commit data by SHA to look up avatar info etc
        commitNames := make(map[string]*user_model.UserCommit)
        // and as blameParts can reference the same commits multiple
@@ -227,7 +239,7 @@ func processBlameParts(ctx *context.Context, blameParts []git.BlamePart) map[str
        return commitNames
 }
 
-func renderBlame(ctx *context.Context, blameParts []git.BlamePart, commitNames map[string]*user_model.UserCommit) {
+func renderBlame(ctx *context.Context, blameParts []*git.BlamePart, commitNames map[string]*user_model.UserCommit) {
        repoLink := ctx.Repo.RepoLink
 
        language := ""