fix

Author: wxiaoguang

routers/web/repo/compare.go

@@ -4,7 +4,6 @@
 package repo
 
 import (
-	"bufio"
 	gocontext "context"
 	"encoding/csv"
 	"errors"
@@ -744,13 +743,16 @@ func attachHiddenCommentIDs(section *gitdiff.DiffSection, lineComments map[int64
 // ExcerptBlob render blob excerpt contents
 func ExcerptBlob(ctx *context.Context) {
 	commitID := ctx.PathParam("sha")
-	lastLeft := ctx.FormInt("last_left")
-	lastRight := ctx.FormInt("last_right")
-	idxLeft := ctx.FormInt("left")
-	idxRight := ctx.FormInt("right")
-	leftHunkSize := ctx.FormInt("left_hunk_size")
-	rightHunkSize := ctx.FormInt("right_hunk_size")
-	direction := ctx.FormString("direction")
+	opts := gitdiff.BlobExcerptOptions{
+		LastLeft:      ctx.FormInt("last_left"),
+		LastRight:     ctx.FormInt("last_right"),
+		LeftIndex:     ctx.FormInt("left"),
+		RightIndex:    ctx.FormInt("right"),
+		LeftHunkSize:  ctx.FormInt("left_hunk_size"),
+		RightHunkSize: ctx.FormInt("right_hunk_size"),
+		Direction:     ctx.FormString("direction"),
+		Language:      ctx.FormString("filelang"),
+	}
 	filePath := ctx.FormString("path")
 	gitRepo := ctx.Repo.GitRepo
 
@@ -770,61 +772,27 @@ func ExcerptBlob(ctx *context.Context) {
 		diffBlobExcerptData.BaseLink = ctx.Repo.RepoLink + "/wiki/blob_excerpt"
 	}
 
-	chunkSize := gitdiff.BlobExcerptChunkSize
 	commit, err := gitRepo.GetCommit(commitID)
 	if err != nil {
-		ctx.HTTPError(http.StatusInternalServerError, "GetCommit")
+		ctx.ServerError("GetCommit", err)
 		return
 	}
-	section := &gitdiff.DiffSection{
-		FileName: filePath,
-	}
-	if direction == "up" && (idxLeft-lastLeft) > chunkSize {
-		idxLeft -= chunkSize
-		idxRight -= chunkSize
-		leftHunkSize += chunkSize
-		rightHunkSize += chunkSize
-		section.Lines, err = getExcerptLines(commit, filePath, idxLeft-1, idxRight-1, chunkSize)
-	} else if direction == "down" && (idxLeft-lastLeft) > chunkSize {
-		section.Lines, err = getExcerptLines(commit, filePath, lastLeft, lastRight, chunkSize)
-		lastLeft += chunkSize
-		lastRight += chunkSize
-	} else {
-		offset := -1
-		if direction == "down" {
-			offset = 0
-		}
-		section.Lines, err = getExcerptLines(commit, filePath, lastLeft, lastRight, idxRight-lastRight+offset)
-		leftHunkSize = 0
-		rightHunkSize = 0
-		idxLeft = lastLeft
-		idxRight = lastRight
+	blob, err := commit.Tree.GetBlobByPath(filePath)
+	if err != nil {
+		ctx.ServerError("GetBlobByPath", err)
+		return
 	}
+	reader, err := blob.DataAsync()
 	if err != nil {
-		ctx.HTTPError(http.StatusInternalServerError, "getExcerptLines")
+		ctx.ServerError("DataAsync", err)
 		return
 	}
+	defer reader.Close()
 
-	newLineSection := &gitdiff.DiffLine{
-		Type: gitdiff.DiffLineSection,
-		SectionInfo: &gitdiff.DiffLineSectionInfo{
-			Path:          filePath,
-			LastLeftIdx:   lastLeft,
-			LastRightIdx:  lastRight,
-			LeftIdx:       idxLeft,
-			RightIdx:      idxRight,
-			LeftHunkSize:  leftHunkSize,
-			RightHunkSize: rightHunkSize,
-		},
-	}
-	if newLineSection.GetExpandDirection() != "" {
-		newLineSection.Content = fmt.Sprintf("@@ -%d,%d +%d,%d @@\n", idxLeft, leftHunkSize, idxRight, rightHunkSize)
-		switch direction {
-		case "up":
-			section.Lines = append([]*gitdiff.DiffLine{newLineSection}, section.Lines...)
-		case "down":
-			section.Lines = append(section.Lines, newLineSection)
-		}
+	section, err := gitdiff.BuildBlobExcerptDiffSection(filePath, reader, opts)
+	if err != nil {
+		ctx.ServerError("BuildBlobExcerptDiffSection", err)
+		return
 	}
 
 	diffBlobExcerptData.PullIssueIndex = ctx.FormInt64("pull_issue_index")
@@ -865,37 +833,3 @@ func ExcerptBlob(ctx *context.Context) {
 
 	ctx.HTML(http.StatusOK, tplBlobExcerpt)
 }
-
-func getExcerptLines(commit *git.Commit, filePath string, idxLeft, idxRight, chunkSize int) ([]*gitdiff.DiffLine, error) {
-	blob, err := commit.Tree.GetBlobByPath(filePath)
-	if err != nil {
-		return nil, err
-	}
-	reader, err := blob.DataAsync()
-	if err != nil {
-		return nil, err
-	}
-	defer reader.Close()
-	scanner := bufio.NewScanner(reader)
-	var diffLines []*gitdiff.DiffLine
-	for line := 0; line < idxRight+chunkSize; line++ {
-		if ok := scanner.Scan(); !ok {
-			break
-		}
-		if line < idxRight {
-			continue
-		}
-		lineText := scanner.Text()
-		diffLine := &gitdiff.DiffLine{
-			LeftIdx:  idxLeft + (line - idxRight) + 1,
-			RightIdx: line + 1,
-			Type:     gitdiff.DiffLinePlain,
-			Content:  " " + lineText,
-		}
-		diffLines = append(diffLines, diffLine)
-	}
-	if err = scanner.Err(); err != nil {
-		return nil, fmt.Errorf("getExcerptLines scan: %w", err)
-	}
-	return diffLines, nil
-}

routers/web/repo/editor_preview.go

@@ -6,12 +6,13 @@ package repo
 import (
 	"net/http"
 
+	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/services/context"
 	files_service "code.gitea.io/gitea/services/repository/files"
 )
 
 func DiffPreviewPost(ctx *context.Context) {
-	content := ctx.FormString("content")
+	newContent := ctx.FormString("content")
 	treePath := files_service.CleanGitTreePath(ctx.Repo.TreePath)
 	if treePath == "" {
 		ctx.HTTPError(http.StatusBadRequest, "file name to diff is invalid")
@@ -27,7 +28,12 @@ func DiffPreviewPost(ctx *context.Context) {
 		return
 	}
 
-	diff, err := files_service.GetDiffPreview(ctx, ctx.Repo.Repository, ctx.Repo.BranchName, treePath, content)
+	oldContent, err := entry.Blob().GetBlobContent(setting.UI.MaxDisplayFileSize)
+	if err != nil {
+		ctx.ServerError("GetBlobBytes", err)
+		return
+	}
+	diff, err := files_service.GetDiffPreview(ctx, ctx.Repo.Repository, ctx.Repo.BranchName, treePath, oldContent, newContent)
 	if err != nil {
 		ctx.ServerError("GetDiffPreview", err)
 		return

services/gitdiff/gitdiff.go

@@ -81,7 +81,8 @@ type DiffLine struct {
 
 // DiffLineSectionInfo represents diff line section meta data
 type DiffLineSectionInfo struct {
-	Path string
+	Path     string
+	language *diffVarMutable[string] // it will be filled later, so it must be a pointer to the DiffFile.language
 
 	// These line "idx" are 1-based line numbers
 	// Left/Right refer to the left/right side of the diff:
@@ -165,15 +166,19 @@ func (d *DiffLine) GetLineTypeMarker() string {
 }
 
 func (d *DiffLine) getBlobExcerptQuery() string {
+	language := ""
+	if d.SectionInfo.language != nil {
+		language = d.SectionInfo.language.value
+	}
 	query := fmt.Sprintf(
 		"last_left=%d&last_right=%d&"+
 			"left=%d&right=%d&"+
 			"left_hunk_size=%d&right_hunk_size=%d&"+
-			"path=%s",
+			"path=%s&filelang=%s",
 		d.SectionInfo.LastLeftIdx, d.SectionInfo.LastRightIdx,
 		d.SectionInfo.LeftIdx, d.SectionInfo.RightIdx,
 		d.SectionInfo.LeftHunkSize, d.SectionInfo.RightHunkSize,
-		url.QueryEscape(d.SectionInfo.Path))
+		url.QueryEscape(d.SectionInfo.Path), url.QueryEscape(language))
 	return query
 }
 
@@ -266,11 +271,12 @@ func FillHiddenCommentIDsForDiffLine(line *DiffLine, lineComments map[int64][]*i
 	line.SectionInfo.HiddenCommentIDs = hiddenCommentIDs
 }
 
-func getDiffLineSectionInfo(treePath, line string, lastLeftIdx, lastRightIdx int) *DiffLineSectionInfo {
+func newDiffLineSectionInfo(curFile *DiffFile, line string, lastLeftIdx, lastRightIdx int) *DiffLineSectionInfo {
 	leftLine, leftHunk, rightLine, rightHunk := git.ParseDiffHunkString(line)
 
 	return &DiffLineSectionInfo{
-		Path:          treePath,
+		Path:          curFile.Name,
+		language:      &curFile.language,
 		LastLeftIdx:   lastLeftIdx,
 		LastRightIdx:  lastRightIdx,
 		LeftIdx:       leftLine,
@@ -290,7 +296,10 @@ func getLineContent(content string, locale translation.Locale) DiffInline {
 
 // DiffSection represents a section of a DiffFile.
 type DiffSection struct {
-	file     *DiffFile
+	language              *diffVarMutable[string]
+	highlightedLeftLines  *diffVarMutable[map[int]template.HTML]
+	highlightedRightLines *diffVarMutable[map[int]template.HTML]
+
 	FileName string
 	Lines    []*DiffLine
 }
@@ -339,9 +348,9 @@ func (diffSection *DiffSection) getDiffLineForRender(diffLineType DiffLineType,
 	var fileLanguage string
 	var highlightedLeftLines, highlightedRightLines map[int]template.HTML
 	// when a "diff section" is manually prepared by ExcerptBlob, it doesn't have "file" information
-	if diffSection.file != nil {
-		fileLanguage = diffSection.file.Language
-		highlightedLeftLines, highlightedRightLines = diffSection.file.highlightedLeftLines, diffSection.file.highlightedRightLines
+	if diffSection.language != nil {
+		fileLanguage = diffSection.language.value
+		highlightedLeftLines, highlightedRightLines = diffSection.highlightedLeftLines.value, diffSection.highlightedRightLines.value
 	}
 
 	var lineHTML template.HTML
@@ -392,6 +401,11 @@ func (diffSection *DiffSection) GetComputedInlineDiffFor(diffLine *DiffLine, loc
 	}
 }
 
+// diffVarMutable is a wrapper to make a variable mutable to be shared across structs
+type diffVarMutable[T any] struct {
+	value T
+}
+
 // DiffFile represents a file diff.
 type DiffFile struct {
 	// only used internally to parse Ambiguous filenames
@@ -418,7 +432,6 @@ type DiffFile struct {
 	IsIncompleteLineTooLong bool
 
 	// will be filled by the extra loop in GitDiffForRender
-	Language          string
 	IsGenerated       bool
 	IsVendored        bool
 	SubmoduleDiffInfo *SubmoduleDiffInfo // IsSubmodule==true, then there must be a SubmoduleDiffInfo
@@ -430,9 +443,10 @@ type DiffFile struct {
 	IsViewed                  bool // User specific
 	HasChangedSinceLastReview bool // User specific
 
-	// for render purpose only, will be filled by the extra loop in GitDiffForRender
-	highlightedLeftLines  map[int]template.HTML
-	highlightedRightLines map[int]template.HTML
+	// for render purpose only, will be filled by the extra loop in GitDiffForRender, they are 0-based
+	language              diffVarMutable[string]
+	highlightedLeftLines  diffVarMutable[map[int]template.HTML]
+	highlightedRightLines diffVarMutable[map[int]template.HTML]
 }
 
 // GetType returns type of diff file.
@@ -470,6 +484,7 @@ func (diffFile *DiffFile) GetTailSectionAndLimitedContent(leftCommit, rightCommi
 		Content: " ",
 		SectionInfo: &DiffLineSectionInfo{
 			Path:         diffFile.Name,
+			language:     &diffFile.language,
 			LastLeftIdx:  lastLine.LeftIdx,
 			LastRightIdx: lastLine.RightIdx,
 			LeftIdx:      leftLineCount,
@@ -907,6 +922,14 @@ func skipToNextDiffHead(input *bufio.Reader) (line string, err error) {
 	return line, err
 }
 
+func newDiffSectionForDiffFile(curFile *DiffFile) *DiffSection {
+	return &DiffSection{
+		language:              &curFile.language,
+		highlightedLeftLines:  &curFile.highlightedLeftLines,
+		highlightedRightLines: &curFile.highlightedRightLines,
+	}
+}
+
 func parseHunks(ctx context.Context, curFile *DiffFile, maxLines, maxLineCharacters int, input *bufio.Reader) (lineBytes []byte, isFragment bool, err error) {
 	sb := strings.Builder{}
 
@@ -964,12 +987,12 @@ func parseHunks(ctx context.Context, curFile *DiffFile, maxLines, maxLineCharact
 			line := sb.String()
 
 			// Create a new section to represent this hunk
-			curSection = &DiffSection{file: curFile}
+			curSection = newDiffSectionForDiffFile(curFile)
 			lastLeftIdx = -1
 			curFile.Sections = append(curFile.Sections, curSection)
 
 			// FIXME: the "-1" can't be right, these "line idx" are all 1-based, maybe there are other bugs that covers this bug.
-			lineSectionInfo := getDiffLineSectionInfo(curFile.Name, line, leftLine-1, rightLine-1)
+			lineSectionInfo := newDiffLineSectionInfo(curFile, line, leftLine-1, rightLine-1)
 			diffLine := &DiffLine{
 				Type:        DiffLineSection,
 				Content:     line,
@@ -1004,7 +1027,7 @@ func parseHunks(ctx context.Context, curFile *DiffFile, maxLines, maxLineCharact
 			rightLine++
 			if curSection == nil {
 				// Create a new section to represent this hunk
-				curSection = &DiffSection{file: curFile}
+				curSection = newDiffSectionForDiffFile(curFile)
 				curFile.Sections = append(curFile.Sections, curSection)
 				lastLeftIdx = -1
 			}
@@ -1037,7 +1060,7 @@ func parseHunks(ctx context.Context, curFile *DiffFile, maxLines, maxLineCharact
 			}
 			if curSection == nil {
 				// Create a new section to represent this hunk
-				curSection = &DiffSection{file: curFile}
+				curSection = newDiffSectionForDiffFile(curFile)
 				curFile.Sections = append(curFile.Sections, curSection)
 				lastLeftIdx = -1
 			}
@@ -1064,7 +1087,7 @@ func parseHunks(ctx context.Context, curFile *DiffFile, maxLines, maxLineCharact
 			lastLeftIdx = -1
 			if curSection == nil {
 				// Create a new section to represent this hunk
-				curSection = &DiffSection{file: curFile}
+				curSection = newDiffSectionForDiffFile(curFile)
 				curFile.Sections = append(curFile.Sections, curSection)
 			}
 			curSection.Lines = append(curSection.Lines, diffLine)
@@ -1309,7 +1332,7 @@ func GetDiffForRender(ctx context.Context, repoLink string, gitRepo *git.Reposit
 			isVendored, isGenerated = attrs.GetVendored(), attrs.GetGenerated()
 			language := attrs.GetLanguage()
 			if language.Has() {
-				diffFile.Language = language.Value()
+				diffFile.language.value = language.Value()
 			}
 			attrDiff = attrs.Get(attribute.Diff).ToString()
 		}
@@ -1336,24 +1359,33 @@ func GetDiffForRender(ctx context.Context, repoLink string, gitRepo *git.Reposit
 		shouldFullFileHighlight := !setting.Git.DisableDiffHighlight && attrDiff.Value() == ""
 		if shouldFullFileHighlight {
 			if limitedContent.LeftContent != nil && limitedContent.LeftContent.buf.Len() < MaxDiffHighlightEntireFileSize {
-				diffFile.highlightedLeftLines = highlightCodeLines(diffFile, true /* left */, limitedContent.LeftContent.buf.Bytes())
+				diffFile.highlightedLeftLines.value = highlightCodeLinesForDiffFile(diffFile, true /* left */, limitedContent.LeftContent.buf.Bytes())
 			}
 			if limitedContent.RightContent != nil && limitedContent.RightContent.buf.Len() < MaxDiffHighlightEntireFileSize {
-				diffFile.highlightedRightLines = highlightCodeLines(diffFile, false /* right */, limitedContent.RightContent.buf.Bytes())
+				diffFile.highlightedRightLines.value = highlightCodeLinesForDiffFile(diffFile, false /* right */, limitedContent.RightContent.buf.Bytes())
 			}
 		}
 	}
 
 	return diff, nil
 }
 
-func highlightCodeLines(diffFile *DiffFile, isLeft bool, rawContent []byte) map[int]template.HTML {
+func FillDiffFileHighlightLinesByContent(diffFile *DiffFile, left, right []byte) {
+	diffFile.highlightedLeftLines.value = highlightCodeLinesForDiffFile(diffFile, true /* left */, left)
+	diffFile.highlightedRightLines.value = highlightCodeLinesForDiffFile(diffFile, false /* right */, right)
+}
+
+func highlightCodeLinesForDiffFile(diffFile *DiffFile, isLeft bool, rawContent []byte) map[int]template.HTML {
+	return highlightCodeLines(diffFile.Name, diffFile.language.value, diffFile.Sections, isLeft, rawContent)
+}
+
+func highlightCodeLines(name, lang string, sections []*DiffSection, isLeft bool, rawContent []byte) map[int]template.HTML {
 	content := util.UnsafeBytesToString(charset.ToUTF8(rawContent, charset.ConvertOpts{}))
-	highlightedNewContent, _ := highlight.RenderCodeFast(diffFile.Name, diffFile.Language, content)
+	highlightedNewContent, _ := highlight.RenderCodeFast(name, lang, content)
 	unsafeLines := highlight.UnsafeSplitHighlightedLines(highlightedNewContent)
 	lines := make(map[int]template.HTML, len(unsafeLines))
 	// only save the highlighted lines we need, but not the whole file, to save memory
-	for _, sec := range diffFile.Sections {
+	for _, sec := range sections {
 		for _, ln := range sec.Lines {
 			lineIdx := ln.LeftIdx
 			if !isLeft {