From 52d333f0841be774b5ed116cd75434814bc09957 Mon Sep 17 00:00:00 2001
From: mrsdizzie <info@mrsdizzie.com>
Date: Wed, 21 Oct 2020 22:37:50 -0400
Subject: [PATCH] Add better error checking for inline html diff code (#13251)
* Fix error in diff html rendering (#13191)
* Fix error in diff html rendering
Was missing an optional whitespace check in regex. Also noticed a rare case where diff.Type == Equal would be empty and thus get a newline attached. Fixed that too.
Fixes #13177
* Update services/gitdiff/gitdiff.go
Co-authored-by: zeripath <art27@cantab.net>
* Update gitdiff_test.go
* fmt
Co-authored-by: zeripath <art27@cantab.net>
* Add better error checking for inline html diff code (#13239)
* Add better error checking for inline html diff code
A better fix for #13191 which cleans up this code a bit and adds basic checking which should avoid writing broken HTML in future situations.
* Update gitdiff_test.go
* better regex
Co-authored-by: zeripath <art27@cantab.net>
---
services/gitdiff/gitdiff.go | 88 +++++++++++++++++++---------------------
services/gitdiff/gitdiff_test.go | 13 +++++-
2 files changed, 53 insertions(+), 48 deletions(-)
diff --git a/services/gitdiff/gitdiff.go b/services/gitdiff/gitdiff.go
index 91105399db..164e1c0ca5 100644
--- a/services/gitdiff/gitdiff.go
+++ b/services/gitdiff/gitdiff.go
@@ -181,64 +181,60 @@ var (
removedCodePrefix = []byte(`<span class="removed-code">`)
codeTagSuffix = []byte(`</span>`)
)
-var addSpanRegex = regexp.MustCompile(`<span [class="[a-z]*]*$`)
+var trailingSpanRegex = regexp.MustCompile(`<span\s*[[:alpha:]="]*?[>]?$`)
+
+// 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 diffToHTML(fileName string, diffs []diffmatchpatch.Diff, lineType DiffLineType) template.HTML {
buf := bytes.NewBuffer(nil)
- var addSpan string
- for i := range diffs {
- switch {
- case diffs[i].Type == diffmatchpatch.DiffEqual:
- // Looking for the case where our 3rd party diff library previously detected a string difference
- // in the middle of a span class because we highlight them first. This happens when added/deleted code
- // also changes the chroma class name, either partially or fully. If found, just move the openining span code forward into the next section
- // see TestDiffToHTML for examples
- if len(addSpan) > 0 {
- diffs[i].Text = addSpan + diffs[i].Text
- addSpan = ""
+ match := ""
+
+ for _, diff := range diffs {
+ if shouldWriteInline(diff, lineType) {
+ if len(match) > 0 {
+ diff.Text = match + diff.Text
+ match = ""
}
- m := addSpanRegex.FindStringSubmatchIndex(diffs[i].Text)
+ // 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, make we manually put it back together
+ // before writing so we don't try insert added/removed code spans in the middle of an existing chroma span
+ // and create broken HTML.
+ m := trailingSpanRegex.FindStringSubmatchIndex(diff.Text)
if m != nil {
- addSpan = diffs[i].Text[m[0]:m[1]]
- buf.WriteString(strings.TrimSuffix(diffs[i].Text, addSpan))
- } else {
- addSpan = ""
- buf.WriteString(getLineContent(diffs[i].Text))
- }
- case diffs[i].Type == diffmatchpatch.DiffInsert && lineType == DiffLineAdd:
- if len(addSpan) > 0 {
- diffs[i].Text = addSpan + diffs[i].Text
- addSpan = ""
+ match = diff.Text[m[0]:m[1]]
+ diff.Text = strings.TrimSuffix(diff.Text, match)
}
- // Print existing closing span first before opening added-code span so it doesn't unintentionally close it
- if strings.HasPrefix(diffs[i].Text, "</span>") {
+ // 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>")
- diffs[i].Text = strings.TrimPrefix(diffs[i].Text, "</span>")
+ diff.Text = strings.TrimPrefix(diff.Text, "</span>")
}
- m := addSpanRegex.FindStringSubmatchIndex(diffs[i].Text)
- if m != nil {
- addSpan = diffs[i].Text[m[0]:m[1]]
- diffs[i].Text = strings.TrimSuffix(diffs[i].Text, addSpan)
+ // 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(getLineContent(diffs[i].Text))
+ buf.WriteString(diff.Text)
buf.Write(codeTagSuffix)
- case diffs[i].Type == diffmatchpatch.DiffDelete && lineType == DiffLineDel:
- if len(addSpan) > 0 {
- diffs[i].Text = addSpan + diffs[i].Text
- addSpan = ""
- }
- if strings.HasPrefix(diffs[i].Text, "</span>") {
- buf.WriteString("</span>")
- diffs[i].Text = strings.TrimPrefix(diffs[i].Text, "</span>")
- }
- m := addSpanRegex.FindStringSubmatchIndex(diffs[i].Text)
- if m != nil {
- addSpan = diffs[i].Text[m[0]:m[1]]
- diffs[i].Text = strings.TrimSuffix(diffs[i].Text, addSpan)
- }
+ case diff.Type == diffmatchpatch.DiffDelete && lineType == DiffLineDel:
buf.Write(removedCodePrefix)
- buf.WriteString(getLineContent(diffs[i].Text))
+ buf.WriteString(diff.Text)
buf.Write(codeTagSuffix)
}
}
diff --git a/services/gitdiff/gitdiff_test.go b/services/gitdiff/gitdiff_test.go
index 64cd4f1c21..e7eeca7004 100644
--- a/services/gitdiff/gitdiff_test.go
+++ b/services/gitdiff/gitdiff_test.go
@@ -50,7 +50,7 @@ func TestDiffToHTML(t *testing.T) {
{Type: dmp.DiffEqual, Text: "</span> <span class=\"p\">{</span>"},
}, DiffLineAdd))
- assertEqual(t, "<span class=\"nx\">tagURL</span> <span class=\"o\">:=</span> <span class=\"removed-code\"><span class=\"nx\">fmt</span><span class=\"p\">.</span><span class=\"nf\">Sprintf</span><span class=\"p\">(</span><span class=\"s\">"## [%s](%s/%s/%s/%s?q=&type=all&state=closed&milestone=%d) - %s"</span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">Milestone\"</span></span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">BaseURL</span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">Owner</span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">Repo</span><span class=\"p\">,</span> <span class=\"nx\"><span class=\"removed-code\">from</span><span class=\"p\">,</span> <span class=\"nx\">milestoneID</span><span class=\"p\">,</span> <span class=\"nx\">time</span><span class=\"p\">.</span><span class=\"nf\">Now</span><span class=\"p\">(</span><span class=\"p\">)</span><span class=\"p\">.</span><span class=\"nf\">Format</span><span class=\"p\">(</span><span class=\"s\">"2006-01-02"</span><span class=\"p\">)</span></span><span class=\"p\">)</span>", diffToHTML("", []dmp.Diff{
+ assertEqual(t, "<span class=\"nx\">tagURL</span> <span class=\"o\">:=</span> <span class=\"removed-code\"><span class=\"nx\">fmt</span><span class=\"p\">.</span><span class=\"nf\">Sprintf</span><span class=\"p\">(</span><span class=\"s\">"## [%s](%s/%s/%s/%s?q=&type=all&state=closed&milestone=%d) - %s"</span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">Milestone\"</span></span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">BaseURL</span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">Owner</span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">Repo</span><span class=\"p\">,</span> <span class=\"removed-code\"><span class=\"nx\">from</span><span class=\"p\">,</span> <span class=\"nx\">milestoneID</span><span class=\"p\">,</span> <span class=\"nx\">time</span><span class=\"p\">.</span><span class=\"nf\">Now</span><span class=\"p\">(</span><span class=\"p\">)</span><span class=\"p\">.</span><span class=\"nf\">Format</span><span class=\"p\">(</span><span class=\"s\">"2006-01-02"</span><span class=\"p\">)</span></span><span class=\"p\">)</span>", diffToHTML("", []dmp.Diff{
{Type: dmp.DiffEqual, Text: "<span class=\"nx\">tagURL</span> <span class=\"o\">:=</span> <span class=\"n"},
{Type: dmp.DiffDelete, Text: "x\">fmt</span><span class=\"p\">.</span><span class=\"nf\">Sprintf</span><span class=\"p\">(</span><span class=\"s\">"## [%s](%s/%s/%s/%s?q=&type=all&state=closed&milestone=%d) - %s"</span><span class=\"p\">,</span> <span class=\"nx\">ge</span><span class=\"p\">.</span><span class=\"nx\">Milestone\""},
{Type: dmp.DiffInsert, Text: "f\">getGiteaTagURL</span><span class=\"p\">(</span><span class=\"nx\">client"},
@@ -60,7 +60,7 @@ func TestDiffToHTML(t *testing.T) {
{Type: dmp.DiffEqual, Text: "</span><span class=\"p\">)</span>"},
}, DiffLineDel))
- assertEqual(t, "<span class=\"nx\">r</span><span class=\"p\">.</span><span class=\"nf\">WrapperRenderer</span><span class=\"p\">(</span><span class=\"nx\">w</span><span class=\"p\">,</span> <span class=\"nx\"><span class=\"removed-code\">language</span></span><span class=\"removed-code\"><span class=\"p\">,</span> <span class=\"kc\">true</span><span class=\"p\">,</span> <span class=\"nx\">attrs</span></span><span class=\"p\">,</span> <span class=\"kc\">false</span><span class=\"p\">)</span>", diffToHTML("", []dmp.Diff{
+ assertEqual(t, "<span class=\"nx\">r</span><span class=\"p\">.</span><span class=\"nf\">WrapperRenderer</span><span class=\"p\">(</span><span class=\"nx\">w</span><span class=\"p\">,</span> <span class=\"removed-code\"><span class=\"nx\">language</span></span><span class=\"removed-code\"><span class=\"p\">,</span> <span class=\"kc\">true</span><span class=\"p\">,</span> <span class=\"nx\">attrs</span></span><span class=\"p\">,</span> <span class=\"kc\">false</span><span class=\"p\">)</span>", diffToHTML("", []dmp.Diff{
{Type: dmp.DiffEqual, Text: "<span class=\"nx\">r</span><span class=\"p\">.</span><span class=\"nf\">WrapperRenderer</span><span class=\"p\">(</span><span class=\"nx\">w</span><span class=\"p\">,</span> <span class=\"nx\">"},
{Type: dmp.DiffDelete, Text: "language</span><span "},
{Type: dmp.DiffEqual, Text: "c"},
@@ -74,6 +74,15 @@ func TestDiffToHTML(t *testing.T) {
{Type: dmp.DiffInsert, Text: "lass=\"p\">,</span> <span class=\"kc\">true</span><span class=\"p\">,</span> <span class=\"nx\">attrs"},
{Type: dmp.DiffEqual, Text: "</span><span class=\"p\">,</span> <span class=\"kc\">false</span><span class=\"p\">)</span>"},
}, DiffLineAdd))
+
+ assertEqual(t, "<span class=\"k\">print</span><span class=\"added-code\"></span><span class=\"added-code\"><span class=\"p\">(</span></span><span class=\"sa\"></span><span class=\"s2\">"</span><span class=\"s2\">// </span><span class=\"s2\">"</span><span class=\"p\">,</span> <span class=\"n\">sys</span><span class=\"o\">.</span><span class=\"n\">argv</span><span class=\"added-code\"><span class=\"p\">)</span></span>", diffToHTML("", []dmp.Diff{
+ {Type: dmp.DiffEqual, Text: "<span class=\"k\">print</span>"},
+ {Type: dmp.DiffInsert, Text: "<span"},
+ {Type: dmp.DiffEqual, Text: " "},
+ {Type: dmp.DiffInsert, Text: "class=\"p\">(</span>"},
+ {Type: dmp.DiffEqual, Text: "<span class=\"sa\"></span><span class=\"s2\">"</span><span class=\"s2\">// </span><span class=\"s2\">"</span><span class=\"p\">,</span> <span class=\"n\">sys</span><span class=\"o\">.</span><span class=\"n\">argv</span>"},
+ {Type: dmp.DiffInsert, Text: "<span class=\"p\">)</span>"},
+ }, DiffLineAdd))
}
func TestParsePatch_singlefile(t *testing.T) {