forgejo-federation/services/gitdiff/gitdiff.go
zeripath beb2058186
Fix broken spans in diffs (#14678)
Gitea runs diff on highlighted code fragment for each line in order to provide
code highlight diffs. Unfortunately this diff algorithm is not aware that span tags
and entities are atomic and cannot be split.

The current fixup code makes some attempt to fix these broken tags however, it cannot
handle situations where a tag is split over multiple blocks.

This PR provides a more algorithmic fixup mechanism whereby spans and entities are
completely coalesced into their respective blocks.

This may result in a incompletely reduced diff but - it will definitely prevent the
broken entities and spans that are currently possible.

As a result of this fixup several inconsistencies were discovered in our testcases
and these were also fixed.

Fix #14231

Signed-off-by: Andrew Thornton <art27@cantab.net>
2021-02-14 15:51:00 +01:00

1224 lines
36 KiB
Go

// Copyright 2014 The Gogs Authors. All rights reserved.
// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package gitdiff
import (
"bufio"
"bytes"
"context"
"fmt"
"html"
"html/template"
"io"
"io/ioutil"
"net/url"
"os"
"os/exec"
"regexp"
"sort"
"strings"
"code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/charset"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/highlight"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/process"
"code.gitea.io/gitea/modules/setting"
"github.com/sergi/go-diff/diffmatchpatch"
stdcharset "golang.org/x/net/html/charset"
"golang.org/x/text/transform"
)
// DiffLineType represents the type of a DiffLine.
type DiffLineType uint8
// DiffLineType possible values.
const (
DiffLinePlain DiffLineType = iota + 1
DiffLineAdd
DiffLineDel
DiffLineSection
)
// DiffFileType represents the type of a DiffFile.
type DiffFileType uint8
// DiffFileType possible values.
const (
DiffFileAdd DiffFileType = iota + 1
DiffFileChange
DiffFileDel
DiffFileRename
DiffFileCopy
)
// DiffLineExpandDirection represents the DiffLineSection expand direction
type DiffLineExpandDirection uint8
// DiffLineExpandDirection possible values.
const (
DiffLineExpandNone DiffLineExpandDirection = iota + 1
DiffLineExpandSingle
DiffLineExpandUpDown
DiffLineExpandUp
DiffLineExpandDown
)
// DiffLine represents a line difference in a DiffSection.
type DiffLine struct {
LeftIdx int
RightIdx int
Type DiffLineType
Content string
Comments []*models.Comment
SectionInfo *DiffLineSectionInfo
}
// DiffLineSectionInfo represents diff line section meta data
type DiffLineSectionInfo struct {
Path string
LastLeftIdx int
LastRightIdx int
LeftIdx int
RightIdx int
LeftHunkSize int
RightHunkSize int
}
// BlobExcerptChunkSize represent max lines of excerpt
const BlobExcerptChunkSize = 20
// GetType returns the type of a DiffLine.
func (d *DiffLine) GetType() int {
return int(d.Type)
}
// CanComment returns whether or not a line can get commented
func (d *DiffLine) CanComment() bool {
return len(d.Comments) == 0 && d.Type != DiffLineSection
}
// GetCommentSide returns the comment side of the first comment, if not set returns empty string
func (d *DiffLine) GetCommentSide() string {
if len(d.Comments) == 0 {
return ""
}
return d.Comments[0].DiffSide()
}
// GetLineTypeMarker returns the line type marker
func (d *DiffLine) GetLineTypeMarker() string {
if strings.IndexByte(" +-", d.Content[0]) > -1 {
return d.Content[0:1]
}
return ""
}
// GetBlobExcerptQuery builds query string to get blob excerpt
func (d *DiffLine) GetBlobExcerptQuery() string {
query := fmt.Sprintf(
"last_left=%d&last_right=%d&"+
"left=%d&right=%d&"+
"left_hunk_size=%d&right_hunk_size=%d&"+
"path=%s",
d.SectionInfo.LastLeftIdx, d.SectionInfo.LastRightIdx,
d.SectionInfo.LeftIdx, d.SectionInfo.RightIdx,
d.SectionInfo.LeftHunkSize, d.SectionInfo.RightHunkSize,
url.QueryEscape(d.SectionInfo.Path))
return query
}
// GetExpandDirection gets DiffLineExpandDirection
func (d *DiffLine) GetExpandDirection() DiffLineExpandDirection {
if d.Type != DiffLineSection || d.SectionInfo == nil || d.SectionInfo.RightIdx-d.SectionInfo.LastRightIdx <= 1 {
return DiffLineExpandNone
}
if d.SectionInfo.LastLeftIdx <= 0 && d.SectionInfo.LastRightIdx <= 0 {
return DiffLineExpandUp
} else if d.SectionInfo.RightIdx-d.SectionInfo.LastRightIdx > BlobExcerptChunkSize && d.SectionInfo.RightHunkSize > 0 {
return DiffLineExpandUpDown
} else if d.SectionInfo.LeftHunkSize <= 0 && d.SectionInfo.RightHunkSize <= 0 {
return DiffLineExpandDown
}
return DiffLineExpandSingle
}
func getDiffLineSectionInfo(treePath, line string, lastLeftIdx, lastRightIdx int) *DiffLineSectionInfo {
leftLine, leftHunk, rightLine, righHunk := git.ParseDiffHunkString(line)
return &DiffLineSectionInfo{
Path: treePath,
LastLeftIdx: lastLeftIdx,
LastRightIdx: lastRightIdx,
LeftIdx: leftLine,
RightIdx: rightLine,
LeftHunkSize: leftHunk,
RightHunkSize: righHunk,
}
}
// escape a line's content or return <br> needed for copy/paste purposes
func getLineContent(content string) string {
if len(content) > 0 {
return html.EscapeString(content)
}
return "<br>"
}
// DiffSection represents a section of a DiffFile.
type DiffSection struct {
FileName string
Name string
Lines []*DiffLine
}
var (
addedCodePrefix = []byte(`<span class="added-code">`)
removedCodePrefix = []byte(`<span class="removed-code">`)
codeTagSuffix = []byte(`</span>`)
)
var unfinishedtagRegex = regexp.MustCompile(`<[^>]*$`)
var trailingSpanRegex = regexp.MustCompile(`<span\s*[[:alpha:]="]*?[>]?$`)
var entityRegex = regexp.MustCompile(`&[#]*?[0-9[:alpha:]]*$`)
// shouldWriteInline represents combinations where we manually write inline changes
func shouldWriteInline(diff diffmatchpatch.Diff, lineType DiffLineType) bool {
if true &&
diff.Type == diffmatchpatch.DiffEqual ||
diff.Type == diffmatchpatch.DiffInsert && lineType == DiffLineAdd ||
diff.Type == diffmatchpatch.DiffDelete && lineType == DiffLineDel {
return true
}
return false
}
func fixupBrokenSpans(diffs []diffmatchpatch.Diff) []diffmatchpatch.Diff {
// Create a new array to store our fixed up blocks
fixedup := make([]diffmatchpatch.Diff, 0, len(diffs))
// semantically label some numbers
const insert, delete, equal = 0, 1, 2
// record the positions of the last type of each block in the fixedup blocks
last := []int{-1, -1, -1}
operation := []diffmatchpatch.Operation{diffmatchpatch.DiffInsert, diffmatchpatch.DiffDelete, diffmatchpatch.DiffEqual}
// create a writer for insert and deletes
toWrite := []strings.Builder{
{},
{},
}
// make some flags for insert and delete
unfinishedTag := []bool{false, false}
unfinishedEnt := []bool{false, false}
// store stores the provided text in the writer for the typ
store := func(text string, typ int) {
(&(toWrite[typ])).WriteString(text)
}
// hasStored returns true if there is stored content
hasStored := func(typ int) bool {
return (&toWrite[typ]).Len() > 0
}
// stored will return that content
stored := func(typ int) string {
return (&toWrite[typ]).String()
}
// empty will empty the stored content
empty := func(typ int) {
(&toWrite[typ]).Reset()
}
// pop will remove the stored content appending to a diff block for that typ
pop := func(typ int, fixedup []diffmatchpatch.Diff) []diffmatchpatch.Diff {
if hasStored(typ) {
if last[typ] > last[equal] {
fixedup[last[typ]].Text += stored(typ)
} else {
fixedup = append(fixedup, diffmatchpatch.Diff{
Type: operation[typ],
Text: stored(typ),
})
}
empty(typ)
}
return fixedup
}
// Now we walk the provided diffs and check the type of each block in turn
for _, diff := range diffs {
typ := delete // flag for handling insert or delete typs
switch diff.Type {
case diffmatchpatch.DiffEqual:
// First check if there is anything stored
if hasStored(insert) || hasStored(delete) {
// There are two reasons for storing content:
// 1. Unfinished Entity <- Could be more efficient here by not doing this if we're looking for a tag
if unfinishedEnt[insert] || unfinishedEnt[delete] {
// we look for a ';' to finish an entity
idx := strings.IndexRune(diff.Text, ';')
if idx >= 0 {
// if we find a ';' store the preceding content to both insert and delete
store(diff.Text[:idx+1], insert)
store(diff.Text[:idx+1], delete)
// and remove it from this block
diff.Text = diff.Text[idx+1:]
// reset the ent flags
unfinishedEnt[insert] = false
unfinishedEnt[delete] = false
} else {
// otherwise store it all on insert and delete
store(diff.Text, insert)
store(diff.Text, delete)
// and empty this block
diff.Text = ""
}
}
// 2. Unfinished Tag
if unfinishedTag[insert] || unfinishedTag[delete] {
// we look for a '>' to finish a tag
idx := strings.IndexRune(diff.Text, '>')
if idx >= 0 {
store(diff.Text[:idx+1], insert)
store(diff.Text[:idx+1], delete)
diff.Text = diff.Text[idx+1:]
unfinishedTag[insert] = false
unfinishedTag[delete] = false
} else {
store(diff.Text, insert)
store(diff.Text, delete)
diff.Text = ""
}
}
// If we've completed the required tag/entities
if !(unfinishedTag[insert] || unfinishedTag[delete] || unfinishedEnt[insert] || unfinishedEnt[delete]) {
// pop off the stack
fixedup = pop(insert, fixedup)
fixedup = pop(delete, fixedup)
}
// If that has left this diff block empty then shortcut
if len(diff.Text) == 0 {
continue
}
}
// check if this block ends in an unfinished tag?
idx := unfinishedtagRegex.FindStringIndex(diff.Text)
if idx != nil {
unfinishedTag[insert] = true
unfinishedTag[delete] = true
} else {
// otherwise does it end in an unfinished entity?
idx = entityRegex.FindStringIndex(diff.Text)
if idx != nil {
unfinishedEnt[insert] = true
unfinishedEnt[delete] = true
}
}
// If there is an unfinished component
if idx != nil {
// Store the fragment
store(diff.Text[idx[0]:], insert)
store(diff.Text[idx[0]:], delete)
// and remove it from this block
diff.Text = diff.Text[:idx[0]]
}
// If that hasn't left the block empty
if len(diff.Text) > 0 {
// store the position of the last equal block and store it in our diffs
last[equal] = len(fixedup)
fixedup = append(fixedup, diff)
}
continue
case diffmatchpatch.DiffInsert:
typ = insert
fallthrough
case diffmatchpatch.DiffDelete:
// First check if there is anything stored for this type
if hasStored(typ) {
// if there is prepend it to this block, empty the storage and reset our flags
diff.Text = stored(typ) + diff.Text
empty(typ)
unfinishedEnt[typ] = false
unfinishedTag[typ] = false
}
// check if this block ends in an unfinished tag
idx := unfinishedtagRegex.FindStringIndex(diff.Text)
if idx != nil {
unfinishedTag[typ] = true
} else {
// otherwise does it end in an unfinished entity
idx = entityRegex.FindStringIndex(diff.Text)
if idx != nil {
unfinishedEnt[typ] = true
}
}
// If there is an unfinished component
if idx != nil {
// Store the fragment
store(diff.Text[idx[0]:], typ)
// and remove it from this block
diff.Text = diff.Text[:idx[0]]
}
// If that hasn't left the block empty
if len(diff.Text) > 0 {
// if the last block of this type was after the last equal block
if last[typ] > last[equal] {
// store this blocks content on that block
fixedup[last[typ]].Text += diff.Text
} else {
// otherwise store the position of the last block of this type and store the block
last[typ] = len(fixedup)
fixedup = append(fixedup, diff)
}
}
continue
}
}
// pop off any remaining stored content
fixedup = pop(insert, fixedup)
fixedup = pop(delete, fixedup)
return fixedup
}
func diffToHTML(fileName string, diffs []diffmatchpatch.Diff, lineType DiffLineType) template.HTML {
buf := bytes.NewBuffer(nil)
match := ""
diffs = fixupBrokenSpans(diffs)
for _, diff := range diffs {
if shouldWriteInline(diff, lineType) {
if len(match) > 0 {
diff.Text = match + diff.Text
match = ""
}
// Chroma HTML syntax highlighting is done before diffing individual lines in order to maintain consistency.
// Since inline changes might split in the middle of a chroma span tag or HTML entity, make we manually put it back together
// before writing so we don't try insert added/removed code spans in the middle of one of those
// and create broken HTML. This is done by moving incomplete HTML forward until it no longer matches our pattern of
// a line ending with an incomplete HTML entity or partial/opening <span>.
// EX:
// diffs[{Type: dmp.DiffDelete, Text: "language</span><span "},
// {Type: dmp.DiffEqual, Text: "c"},
// {Type: dmp.DiffDelete, Text: "lass="p">}]
// After first iteration
// diffs[{Type: dmp.DiffDelete, Text: "language</span>"}, //write out
// {Type: dmp.DiffEqual, Text: "<span c"},
// {Type: dmp.DiffDelete, Text: "lass="p">,</span>}]
// After second iteration
// {Type: dmp.DiffEqual, Text: ""}, // write out
// {Type: dmp.DiffDelete, Text: "<span class="p">,</span>}]
// Final
// {Type: dmp.DiffDelete, Text: "<span class="p">,</span>}]
// end up writing <span class="removed-code"><span class="p">,</span></span>
// Instead of <span class="removed-code">lass="p",</span></span>
m := trailingSpanRegex.FindStringSubmatchIndex(diff.Text)
if m != nil {
match = diff.Text[m[0]:m[1]]
diff.Text = strings.TrimSuffix(diff.Text, match)
}
m = entityRegex.FindStringSubmatchIndex(diff.Text)
if m != nil {
match = diff.Text[m[0]:m[1]]
diff.Text = strings.TrimSuffix(diff.Text, match)
}
// Print an existing closing span first before opening added/remove-code span so it doesn't unintentionally close it
if strings.HasPrefix(diff.Text, "</span>") {
buf.WriteString("</span>")
diff.Text = strings.TrimPrefix(diff.Text, "</span>")
}
// If we weren't able to fix it then this should avoid broken HTML by not inserting more spans below
// The previous/next diff section will contain the rest of the tag that is missing here
if strings.Count(diff.Text, "<") != strings.Count(diff.Text, ">") {
buf.WriteString(diff.Text)
continue
}
}
switch {
case diff.Type == diffmatchpatch.DiffEqual:
buf.WriteString(diff.Text)
case diff.Type == diffmatchpatch.DiffInsert && lineType == DiffLineAdd:
buf.Write(addedCodePrefix)
buf.WriteString(diff.Text)
buf.Write(codeTagSuffix)
case diff.Type == diffmatchpatch.DiffDelete && lineType == DiffLineDel:
buf.Write(removedCodePrefix)
buf.WriteString(diff.Text)
buf.Write(codeTagSuffix)
}
}
return template.HTML(buf.Bytes())
}
// GetLine gets a specific line by type (add or del) and file line number
func (diffSection *DiffSection) GetLine(lineType DiffLineType, idx int) *DiffLine {
var (
difference = 0
addCount = 0
delCount = 0
matchDiffLine *DiffLine
)
LOOP:
for _, diffLine := range diffSection.Lines {
switch diffLine.Type {
case DiffLineAdd:
addCount++
case DiffLineDel:
delCount++
default:
if matchDiffLine != nil {
break LOOP
}
difference = diffLine.RightIdx - diffLine.LeftIdx
addCount = 0
delCount = 0
}
switch lineType {
case DiffLineDel:
if diffLine.RightIdx == 0 && diffLine.LeftIdx == idx-difference {
matchDiffLine = diffLine
}
case DiffLineAdd:
if diffLine.LeftIdx == 0 && diffLine.RightIdx == idx+difference {
matchDiffLine = diffLine
}
}
}
if addCount == delCount {
return matchDiffLine
}
return nil
}
var diffMatchPatch = diffmatchpatch.New()
func init() {
diffMatchPatch.DiffEditCost = 100
}
// GetComputedInlineDiffFor computes inline diff for the given line.
func (diffSection *DiffSection) GetComputedInlineDiffFor(diffLine *DiffLine) template.HTML {
if setting.Git.DisableDiffHighlight {
return template.HTML(getLineContent(diffLine.Content[1:]))
}
var (
compareDiffLine *DiffLine
diff1 string
diff2 string
)
// try to find equivalent diff line. ignore, otherwise
switch diffLine.Type {
case DiffLineSection:
return template.HTML(getLineContent(diffLine.Content[1:]))
case DiffLineAdd:
compareDiffLine = diffSection.GetLine(DiffLineDel, diffLine.RightIdx)
if compareDiffLine == nil {
return template.HTML(highlight.Code(diffSection.FileName, diffLine.Content[1:]))
}
diff1 = compareDiffLine.Content
diff2 = diffLine.Content
case DiffLineDel:
compareDiffLine = diffSection.GetLine(DiffLineAdd, diffLine.LeftIdx)
if compareDiffLine == nil {
return template.HTML(highlight.Code(diffSection.FileName, diffLine.Content[1:]))
}
diff1 = diffLine.Content
diff2 = compareDiffLine.Content
default:
if strings.IndexByte(" +-", diffLine.Content[0]) > -1 {
return template.HTML(highlight.Code(diffSection.FileName, diffLine.Content[1:]))
}
return template.HTML(highlight.Code(diffSection.FileName, diffLine.Content))
}
diffRecord := diffMatchPatch.DiffMain(highlight.Code(diffSection.FileName, diff1[1:]), highlight.Code(diffSection.FileName, diff2[1:]), true)
diffRecord = diffMatchPatch.DiffCleanupEfficiency(diffRecord)
return diffToHTML(diffSection.FileName, diffRecord, diffLine.Type)
}
// DiffFile represents a file diff.
type DiffFile struct {
Name string
OldName string
Index int
Addition, Deletion int
Type DiffFileType
IsCreated bool
IsDeleted bool
IsBin bool
IsLFSFile bool
IsRenamed bool
IsSubmodule bool
Sections []*DiffSection
IsIncomplete bool
IsProtected bool
}
// GetType returns type of diff file.
func (diffFile *DiffFile) GetType() int {
return int(diffFile.Type)
}
// GetTailSection creates a fake DiffLineSection if the last section is not the end of the file
func (diffFile *DiffFile) GetTailSection(gitRepo *git.Repository, leftCommitID, rightCommitID string) *DiffSection {
if len(diffFile.Sections) == 0 || diffFile.Type != DiffFileChange || diffFile.IsBin || diffFile.IsLFSFile {
return nil
}
leftCommit, err := gitRepo.GetCommit(leftCommitID)
if err != nil {
return nil
}
rightCommit, err := gitRepo.GetCommit(rightCommitID)
if err != nil {
return nil
}
lastSection := diffFile.Sections[len(diffFile.Sections)-1]
lastLine := lastSection.Lines[len(lastSection.Lines)-1]
leftLineCount := getCommitFileLineCount(leftCommit, diffFile.Name)
rightLineCount := getCommitFileLineCount(rightCommit, diffFile.Name)
if leftLineCount <= lastLine.LeftIdx || rightLineCount <= lastLine.RightIdx {
return nil
}
tailDiffLine := &DiffLine{
Type: DiffLineSection,
Content: " ",
SectionInfo: &DiffLineSectionInfo{
Path: diffFile.Name,
LastLeftIdx: lastLine.LeftIdx,
LastRightIdx: lastLine.RightIdx,
LeftIdx: leftLineCount,
RightIdx: rightLineCount,
}}
tailSection := &DiffSection{FileName: diffFile.Name, Lines: []*DiffLine{tailDiffLine}}
return tailSection
}
func getCommitFileLineCount(commit *git.Commit, filePath string) int {
blob, err := commit.GetBlobByPath(filePath)
if err != nil {
return 0
}
lineCount, err := blob.GetBlobLineCount()
if err != nil {
return 0
}
return lineCount
}
// Diff represents a difference between two git trees.
type Diff struct {
NumFiles, TotalAddition, TotalDeletion int
Files []*DiffFile
IsIncomplete bool
}
// LoadComments loads comments into each line
func (diff *Diff) LoadComments(issue *models.Issue, currentUser *models.User) error {
allComments, err := models.FetchCodeComments(issue, currentUser)
if err != nil {
return err
}
for _, file := range diff.Files {
if lineCommits, ok := allComments[file.Name]; ok {
for _, section := range file.Sections {
for _, line := range section.Lines {
if comments, ok := lineCommits[int64(line.LeftIdx*-1)]; ok {
line.Comments = append(line.Comments, comments...)
}
if comments, ok := lineCommits[int64(line.RightIdx)]; ok {
line.Comments = append(line.Comments, comments...)
}
sort.SliceStable(line.Comments, func(i, j int) bool {
return line.Comments[i].CreatedUnix < line.Comments[j].CreatedUnix
})
}
}
}
}
return nil
}
const cmdDiffHead = "diff --git "
// ParsePatch builds a Diff object from a io.Reader and some parameters.
func ParsePatch(maxLines, maxLineCharacters, maxFiles int, reader io.Reader) (*Diff, error) {
var curFile *DiffFile
diff := &Diff{Files: make([]*DiffFile, 0)}
sb := strings.Builder{}
// OK let's set a reasonable buffer size.
// This should be let's say at least the size of maxLineCharacters or 4096 whichever is larger.
readerSize := maxLineCharacters
if readerSize < 4096 {
readerSize = 4096
}
input := bufio.NewReaderSize(reader, readerSize)
line, err := input.ReadString('\n')
if err != nil {
if err == io.EOF {
return diff, nil
}
return diff, err
}
parsingLoop:
for {
// 1. A patch file always begins with `diff --git ` + `a/path b/path` (possibly quoted)
// if it does not we have bad input!
if !strings.HasPrefix(line, cmdDiffHead) {
return diff, fmt.Errorf("Invalid first file line: %s", line)
}
// TODO: Handle skipping first n files
if len(diff.Files) >= maxFiles {
diff.IsIncomplete = true
_, err := io.Copy(ioutil.Discard, reader)
if err != nil {
// By the definition of io.Copy this never returns io.EOF
return diff, fmt.Errorf("Copy: %v", err)
}
break parsingLoop
}
curFile = createDiffFile(diff, line)
diff.Files = append(diff.Files, curFile)
// 2. It is followed by one or more extended header lines:
//
// old mode <mode>
// new mode <mode>
// deleted file mode <mode>
// new file mode <mode>
// copy from <path>
// copy to <path>
// rename from <path>
// rename to <path>
// similarity index <number>
// dissimilarity index <number>
// index <hash>..<hash> <mode>
//
// * <mode> 6-digit octal numbers including the file type and file permission bits.
// * <path> does not include the a/ and b/ prefixes
// * <number> percentage of unchanged lines for similarity, percentage of changed
// lines dissimilarity as integer rounded down with terminal %. 100% => equal files.
// * The index line includes the blob object names before and after the change.
// The <mode> is included if the file mode does not change; otherwise, separate
// lines indicate the old and the new mode.
// 3. Following this header the "standard unified" diff format header may be encountered: (but not for every case...)
//
// --- a/<path>
// +++ b/<path>
//
// With multiple hunks
//
// @@ <hunk descriptor> @@
// +added line
// -removed line
// unchanged line
//
// 4. Binary files get:
//
// Binary files a/<path> and b/<path> differ
//
// but one of a/<path> and b/<path> could be /dev/null.
curFileLoop:
for {
line, err = input.ReadString('\n')
if err != nil {
if err != io.EOF {
return diff, err
}
break parsingLoop
}
switch {
case strings.HasPrefix(line, cmdDiffHead):
break curFileLoop
case strings.HasPrefix(line, "old mode ") ||
strings.HasPrefix(line, "new mode "):
if strings.HasSuffix(line, " 160000\n") {
curFile.IsSubmodule = true
}
case strings.HasPrefix(line, "copy from "):
curFile.IsRenamed = true
curFile.Type = DiffFileCopy
case strings.HasPrefix(line, "copy to "):
curFile.IsRenamed = true
curFile.Type = DiffFileCopy
case strings.HasPrefix(line, "new file"):
curFile.Type = DiffFileAdd
curFile.IsCreated = true
if strings.HasSuffix(line, " 160000\n") {
curFile.IsSubmodule = true
}
case strings.HasPrefix(line, "deleted"):
curFile.Type = DiffFileDel
curFile.IsDeleted = true
if strings.HasSuffix(line, " 160000\n") {
curFile.IsSubmodule = true
}
case strings.HasPrefix(line, "index"):
if strings.HasSuffix(line, " 160000\n") {
curFile.IsSubmodule = true
}
case strings.HasPrefix(line, "similarity index 100%"):
curFile.Type = DiffFileRename
case strings.HasPrefix(line, "Binary"):
curFile.IsBin = true
case strings.HasPrefix(line, "--- "):
// Do nothing with this line
case strings.HasPrefix(line, "+++ "):
// Do nothing with this line
lineBytes, isFragment, err := parseHunks(curFile, maxLines, maxLineCharacters, input)
diff.TotalAddition += curFile.Addition
diff.TotalDeletion += curFile.Deletion
if err != nil {
if err != io.EOF {
return diff, err
}
break parsingLoop
}
sb.Reset()
_, _ = sb.Write(lineBytes)
for isFragment {
lineBytes, isFragment, err = input.ReadLine()
if err != nil {
// Now by the definition of ReadLine this cannot be io.EOF
return diff, fmt.Errorf("Unable to ReadLine: %v", err)
}
_, _ = sb.Write(lineBytes)
}
line = sb.String()
sb.Reset()
break curFileLoop
}
}
}
// FIXME: There are numerous issues with this:
// - we might want to consider detecting encoding while parsing but...
// - we're likely to fail to get the correct encoding here anyway as we won't have enough information
// - and this doesn't really account for changes in encoding
var buf bytes.Buffer
for _, f := range diff.Files {
buf.Reset()
for _, sec := range f.Sections {
for _, l := range sec.Lines {
if l.Type == DiffLineSection {
continue
}
buf.WriteString(l.Content[1:])
buf.WriteString("\n")
}
}
charsetLabel, err := charset.DetectEncoding(buf.Bytes())
if charsetLabel != "UTF-8" && err == nil {
encoding, _ := stdcharset.Lookup(charsetLabel)
if encoding != nil {
d := encoding.NewDecoder()
for _, sec := range f.Sections {
for _, l := range sec.Lines {
if l.Type == DiffLineSection {
continue
}
if c, _, err := transform.String(d, l.Content[1:]); err == nil {
l.Content = l.Content[0:1] + c
}
}
}
}
}
}
diff.NumFiles = len(diff.Files)
return diff, nil
}
func parseHunks(curFile *DiffFile, maxLines, maxLineCharacters int, input *bufio.Reader) (lineBytes []byte, isFragment bool, err error) {
sb := strings.Builder{}
var (
curSection *DiffSection
curFileLinesCount int
curFileLFSPrefix bool
)
leftLine, rightLine := 1, 1
for {
for isFragment {
curFile.IsIncomplete = true
_, isFragment, err = input.ReadLine()
if err != nil {
// Now by the definition of ReadLine this cannot be io.EOF
err = fmt.Errorf("Unable to ReadLine: %v", err)
return
}
}
sb.Reset()
lineBytes, isFragment, err = input.ReadLine()
if err != nil {
if err == io.EOF {
return
}
err = fmt.Errorf("Unable to ReadLine: %v", err)
return
}
if lineBytes[0] == 'd' {
// End of hunks
return
}
switch lineBytes[0] {
case '@':
if curFileLinesCount >= maxLines {
curFile.IsIncomplete = true
continue
}
_, _ = sb.Write(lineBytes)
for isFragment {
// This is very odd indeed - we're in a section header and the line is too long
// This really shouldn't happen...
lineBytes, isFragment, err = input.ReadLine()
if err != nil {
// Now by the definition of ReadLine this cannot be io.EOF
err = fmt.Errorf("Unable to ReadLine: %v", err)
return
}
_, _ = sb.Write(lineBytes)
}
line := sb.String()
// Create a new section to represent this hunk
curSection = &DiffSection{}
curFile.Sections = append(curFile.Sections, curSection)
lineSectionInfo := getDiffLineSectionInfo(curFile.Name, line, leftLine-1, rightLine-1)
diffLine := &DiffLine{
Type: DiffLineSection,
Content: line,
SectionInfo: lineSectionInfo,
}
curSection.Lines = append(curSection.Lines, diffLine)
curSection.FileName = curFile.Name
// update line number.
leftLine = lineSectionInfo.LeftIdx
rightLine = lineSectionInfo.RightIdx
continue
case '\\':
if curFileLinesCount >= maxLines {
curFile.IsIncomplete = true
continue
}
// This is used only to indicate that the current file does not have a terminal newline
if !bytes.Equal(lineBytes, []byte("\\ No newline at end of file")) {
err = fmt.Errorf("Unexpected line in hunk: %s", string(lineBytes))
return
}
// Technically this should be the end the file!
// FIXME: we should be putting a marker at the end of the file if there is no terminal new line
continue
case '+':
curFileLinesCount++
curFile.Addition++
if curFileLinesCount >= maxLines {
curFile.IsIncomplete = true
continue
}
diffLine := &DiffLine{Type: DiffLineAdd, RightIdx: rightLine}
rightLine++
curSection.Lines = append(curSection.Lines, diffLine)
case '-':
curFileLinesCount++
curFile.Deletion++
if curFileLinesCount >= maxLines {
curFile.IsIncomplete = true
continue
}
diffLine := &DiffLine{Type: DiffLineDel, LeftIdx: leftLine}
if leftLine > 0 {
leftLine++
}
curSection.Lines = append(curSection.Lines, diffLine)
case ' ':
curFileLinesCount++
if curFileLinesCount >= maxLines {
curFile.IsIncomplete = true
continue
}
diffLine := &DiffLine{Type: DiffLinePlain, LeftIdx: leftLine, RightIdx: rightLine}
leftLine++
rightLine++
curSection.Lines = append(curSection.Lines, diffLine)
default:
// This is unexpected
err = fmt.Errorf("Unexpected line in hunk: %s", string(lineBytes))
return
}
line := string(lineBytes)
if isFragment {
curFile.IsIncomplete = true
for isFragment {
lineBytes, isFragment, err = input.ReadLine()
if err != nil {
// Now by the definition of ReadLine this cannot be io.EOF
err = fmt.Errorf("Unable to ReadLine: %v", err)
return
}
}
}
if len(line) > maxLineCharacters {
curFile.IsIncomplete = true
line = line[:maxLineCharacters]
}
curSection.Lines[len(curSection.Lines)-1].Content = line
// handle LFS
if line[1:] == models.LFSMetaFileIdentifier {
curFileLFSPrefix = true
} else if curFileLFSPrefix && strings.HasPrefix(line[1:], models.LFSMetaFileOidPrefix) {
oid := strings.TrimPrefix(line[1:], models.LFSMetaFileOidPrefix)
if len(oid) == 64 {
m := &models.LFSMetaObject{Oid: oid}
count, err := models.Count(m)
if err == nil && count > 0 {
curFile.IsBin = true
curFile.IsLFSFile = true
curSection.Lines = nil
}
}
}
}
}
func createDiffFile(diff *Diff, line string) *DiffFile {
// The a/ and b/ filenames are the same unless rename/copy is involved.
// Especially, even for a creation or a deletion, /dev/null is not used
// in place of the a/ or b/ filenames.
//
// When rename/copy is involved, file1 and file2 show the name of the
// source file of the rename/copy and the name of the file that rename/copy
// produces, respectively.
//
// Path names are quoted if necessary.
//
// This means that you should always be able to determine the file name even when there
// there is potential ambiguity...
//
// but we can be simpler with our heuristics by just forcing git to prefix things nicely
curFile := &DiffFile{
Index: len(diff.Files) + 1,
Type: DiffFileChange,
Sections: make([]*DiffSection, 0, 10),
}
rd := strings.NewReader(line[len(cmdDiffHead):] + " ")
curFile.Type = DiffFileChange
curFile.OldName = readFileName(rd)
curFile.Name = readFileName(rd)
curFile.IsRenamed = curFile.Name != curFile.OldName
return curFile
}
func readFileName(rd *strings.Reader) string {
var name string
char, _ := rd.ReadByte()
_ = rd.UnreadByte()
if char == '"' {
fmt.Fscanf(rd, "%q ", &name)
if name[0] == '\\' {
name = name[1:]
}
} else {
fmt.Fscanf(rd, "%s ", &name)
}
return name[2:]
}
// GetDiffRange builds a Diff between two commits of a repository.
// passing the empty string as beforeCommitID returns a diff from the
// parent commit.
func GetDiffRange(repoPath, beforeCommitID, afterCommitID string, maxLines, maxLineCharacters, maxFiles int) (*Diff, error) {
return GetDiffRangeWithWhitespaceBehavior(repoPath, beforeCommitID, afterCommitID, maxLines, maxLineCharacters, maxFiles, "")
}
// GetDiffRangeWithWhitespaceBehavior builds a Diff between two commits of a repository.
// Passing the empty string as beforeCommitID returns a diff from the parent commit.
// The whitespaceBehavior is either an empty string or a git flag
func GetDiffRangeWithWhitespaceBehavior(repoPath, beforeCommitID, afterCommitID string, maxLines, maxLineCharacters, maxFiles int, whitespaceBehavior string) (*Diff, error) {
gitRepo, err := git.OpenRepository(repoPath)
if err != nil {
return nil, err
}
defer gitRepo.Close()
commit, err := gitRepo.GetCommit(afterCommitID)
if err != nil {
return nil, err
}
// FIXME: graceful: These commands should likely have a timeout
ctx, cancel := context.WithCancel(git.DefaultContext)
defer cancel()
var cmd *exec.Cmd
if (len(beforeCommitID) == 0 || beforeCommitID == git.EmptySHA) && commit.ParentCount() == 0 {
diffArgs := []string{"diff", "--src-prefix=\\a/", "--dst-prefix=\\b/", "-M"}
if len(whitespaceBehavior) != 0 {
diffArgs = append(diffArgs, whitespaceBehavior)
}
// append empty tree ref
diffArgs = append(diffArgs, "4b825dc642cb6eb9a060e54bf8d69288fbee4904")
diffArgs = append(diffArgs, afterCommitID)
cmd = exec.CommandContext(ctx, git.GitExecutable, diffArgs...)
} else {
actualBeforeCommitID := beforeCommitID
if len(actualBeforeCommitID) == 0 {
parentCommit, _ := commit.Parent(0)
actualBeforeCommitID = parentCommit.ID.String()
}
diffArgs := []string{"diff", "--src-prefix=\\a/", "--dst-prefix=\\b/", "-M"}
if len(whitespaceBehavior) != 0 {
diffArgs = append(diffArgs, whitespaceBehavior)
}
diffArgs = append(diffArgs, actualBeforeCommitID)
diffArgs = append(diffArgs, afterCommitID)
cmd = exec.CommandContext(ctx, git.GitExecutable, diffArgs...)
beforeCommitID = actualBeforeCommitID
}
cmd.Dir = repoPath
cmd.Stderr = os.Stderr
stdout, err := cmd.StdoutPipe()
if err != nil {
return nil, fmt.Errorf("StdoutPipe: %v", err)
}
if err = cmd.Start(); err != nil {
return nil, fmt.Errorf("Start: %v", err)
}
pid := process.GetManager().Add(fmt.Sprintf("GetDiffRange [repo_path: %s]", repoPath), cancel)
defer process.GetManager().Remove(pid)
diff, err := ParsePatch(maxLines, maxLineCharacters, maxFiles, stdout)
if err != nil {
return nil, fmt.Errorf("ParsePatch: %v", err)
}
for _, diffFile := range diff.Files {
tailSection := diffFile.GetTailSection(gitRepo, beforeCommitID, afterCommitID)
if tailSection != nil {
diffFile.Sections = append(diffFile.Sections, tailSection)
}
}
if err = cmd.Wait(); err != nil {
return nil, fmt.Errorf("Wait: %v", err)
}
shortstatArgs := []string{beforeCommitID + "..." + afterCommitID}
if len(beforeCommitID) == 0 || beforeCommitID == git.EmptySHA {
shortstatArgs = []string{git.EmptyTreeSHA, afterCommitID}
}
diff.NumFiles, diff.TotalAddition, diff.TotalDeletion, err = git.GetDiffShortStat(repoPath, shortstatArgs...)
if err != nil && strings.Contains(err.Error(), "no merge base") {
// git >= 2.28 now returns an error if base and head have become unrelated.
// previously it would return the results of git diff --shortstat base head so let's try that...
shortstatArgs = []string{beforeCommitID, afterCommitID}
diff.NumFiles, diff.TotalAddition, diff.TotalDeletion, err = git.GetDiffShortStat(repoPath, shortstatArgs...)
}
if err != nil {
return nil, err
}
return diff, nil
}
// GetDiffCommit builds a Diff representing the given commitID.
func GetDiffCommit(repoPath, commitID string, maxLines, maxLineCharacters, maxFiles int) (*Diff, error) {
return GetDiffRangeWithWhitespaceBehavior(repoPath, "", commitID, maxLines, maxLineCharacters, maxFiles, "")
}
// GetDiffCommitWithWhitespaceBehavior builds a Diff representing the given commitID.
// The whitespaceBehavior is either an empty string or a git flag
func GetDiffCommitWithWhitespaceBehavior(repoPath, commitID string, maxLines, maxLineCharacters, maxFiles int, whitespaceBehavior string) (*Diff, error) {
return GetDiffRangeWithWhitespaceBehavior(repoPath, "", commitID, maxLines, maxLineCharacters, maxFiles, whitespaceBehavior)
}
// CommentAsDiff returns c.Patch as *Diff
func CommentAsDiff(c *models.Comment) (*Diff, error) {
diff, err := ParsePatch(setting.Git.MaxGitDiffLines,
setting.Git.MaxGitDiffLineCharacters, setting.Git.MaxGitDiffFiles, strings.NewReader(c.Patch))
if err != nil {
return nil, err
}
if len(diff.Files) == 0 {
return nil, fmt.Errorf("no file found for comment ID: %d", c.ID)
}
secs := diff.Files[0].Sections
if len(secs) == 0 {
return nil, fmt.Errorf("no sections found for comment ID: %d", c.ID)
}
return diff, nil
}
// CommentMustAsDiff executes AsDiff and logs the error instead of returning
func CommentMustAsDiff(c *models.Comment) *Diff {
diff, err := CommentAsDiff(c)
if err != nil {
log.Warn("CommentMustAsDiff: %v", err)
}
return diff
}
// GetWhitespaceFlag returns git diff flag for treating whitespaces
func GetWhitespaceFlag(whiteSpaceBehavior string) string {
whitespaceFlags := map[string]string{
"ignore-all": "-w",
"ignore-change": "-b",
"ignore-eol": "--ignore-space-at-eol",
"": ""}
return whitespaceFlags[whiteSpaceBehavior]
}