fix(sanitize): preserve visible characters in title fields

pkg/errors/error.go

@@ -257,7 +257,7 @@ func formatGitHubValidationDetail(validationErr github.Error) string {
 
 func sanitizeGitHubValidationText(value string) string {
 	// Tool errors are plain text; keep quoted branch patterns readable.
-	sanitized := strings.ReplaceAll(sanitize.Sanitize(value), "'", "'")
+	sanitized := sanitize.Title(value)
 	return strings.Join(strings.Fields(sanitized), " ")
 }
 

pkg/github/discussions.go

@@ -100,7 +100,7 @@ type WithCategoryNoOrder struct {
 func fragmentToDiscussion(fragment NodeFragment) *github.Discussion {
 	return &github.Discussion{
 		Number:    github.Ptr(int(fragment.Number)),
-		Title:     github.Ptr(sanitize.Sanitize(string(fragment.Title))),
+		Title:     github.Ptr(sanitize.Title(string(fragment.Title))),
 		HTMLURL:   github.Ptr(string(fragment.URL)),
 		CreatedAt: &github.Timestamp{Time: fragment.CreatedAt.Time},
 		UpdatedAt: &github.Timestamp{Time: fragment.UpdatedAt.Time},
@@ -361,7 +361,7 @@ func GetDiscussion(t translations.TranslationHelperFunc) inventory.ServerTool {
 			// like ListDiscussions and GetDiscussionComments).
 			response := map[string]any{
 				"number":     int(d.Number),
-				"title":      sanitize.Sanitize(string(d.Title)),
+				"title":      sanitize.Title(string(d.Title)),
 				"body":       sanitize.Sanitize(string(d.Body)),
 				"url":        string(d.URL),
 				"closed":     bool(d.Closed),

pkg/github/issues.go

@@ -1194,7 +1194,7 @@ func GetIssueParent(ctx context.Context, client *githubv4.Client, deps ToolDepen
 	return MarshalledTextResult(map[string]any{
 		"parent": map[string]any{
 			"number":     int(parent.Number),
-			"title":      sanitize.Sanitize(string(parent.Title)),
+			"title":      sanitize.Title(string(parent.Title)),
 			"state":      string(parent.State),
 			"url":        string(parent.URL),
 			"repository": string(parent.Repository.NameWithOwner),
@@ -1995,7 +1995,7 @@ func sanitizeIssueTitleAndBody(issue *github.Issue) {
 		return
 	}
 	if issue.Title != nil {
-		issue.Title = github.Ptr(sanitize.Sanitize(*issue.Title))
+		issue.Title = github.Ptr(sanitize.Title(*issue.Title))
 	}
 	if issue.Body != nil {
 		issue.Body = github.Ptr(sanitize.Sanitize(*issue.Body))

pkg/github/minimal_types.go

@@ -622,7 +622,7 @@ type MinimalPullRequestRef struct {
 func newMinimalPullRequestRef(number int, title, state, url, repository string) MinimalPullRequestRef {
 	return MinimalPullRequestRef{
 		Number:     number,
-		Title:      sanitize.Sanitize(title),
+		Title:      sanitize.Title(title),
 		State:      state,
 		URL:        url,
 		Repository: repository,
@@ -646,7 +646,7 @@ type MinimalIssueRef struct {
 func newMinimalIssueRef(number int, title, state, url, repository string) MinimalIssueRef {
 	return MinimalIssueRef{
 		Number:     number,
-		Title:      sanitize.Sanitize(title),
+		Title:      sanitize.Title(title),
 		State:      state,
 		URL:        url,
 		Repository: repository,
@@ -814,7 +814,7 @@ func convertToMinimalPullRequestReview(review *github.PullRequestReview) Minimal
 func convertToMinimalIssue(issue *github.Issue) MinimalIssue {
 	m := MinimalIssue{
 		Number:            issue.GetNumber(),
-		Title:             sanitize.Sanitize(issue.GetTitle()),
+		Title:             sanitize.Title(issue.GetTitle()),
 		Body:              sanitize.Sanitize(issue.GetBody()),
 		State:             issue.GetState(),
 		StateReason:       issue.GetStateReason(),
@@ -925,7 +925,7 @@ func fragmentToMinimalIssue(fragment IssueFragment) MinimalIssue {
 func fragmentWithoutFieldValuesToMinimalIssue(fragment issueFragmentWithoutFieldValues) MinimalIssue {
 	m := MinimalIssue{
 		Number:    int(fragment.Number),
-		Title:     sanitize.Sanitize(string(fragment.Title)),
+		Title:     sanitize.Title(string(fragment.Title)),
 		Body:      sanitize.Sanitize(string(fragment.Body)),
 		State:     string(fragment.State),
 		Comments:  int(fragment.Comments.TotalCount),
@@ -1084,7 +1084,7 @@ func convertToMinimalFileContentResponse(resp *github.RepositoryContentResponse)
 func convertToMinimalPullRequest(pr *github.PullRequest) MinimalPullRequest {
 	m := MinimalPullRequest{
 		Number:         pr.GetNumber(),
-		Title:          sanitize.Sanitize(pr.GetTitle()),
+		Title:          sanitize.Title(pr.GetTitle()),
 		Body:           sanitize.Sanitize(pr.GetBody()),
 		State:          pr.GetState(),
 		Draft:          pr.GetDraft(),
@@ -1279,7 +1279,7 @@ func convertIssueToMinimalProjectItemContent(issue *github.Issue) *MinimalProjec
 		ID:          issue.GetID(),
 		NodeID:      issue.GetNodeID(),
 		Number:      issue.GetNumber(),
-		Title:       sanitize.Sanitize(issue.GetTitle()),
+		Title:       sanitize.Title(issue.GetTitle()),
 		State:       issue.GetState(),
 		StateReason: issue.GetStateReason(),
 		HTMLURL:     issue.GetHTMLURL(),
@@ -1316,7 +1316,7 @@ func convertPullRequestToMinimalProjectItemContent(pr *github.PullRequest) *Mini
 		ID:         pr.GetID(),
 		NodeID:     pr.GetNodeID(),
 		Number:     pr.GetNumber(),
-		Title:      sanitize.Sanitize(pr.GetTitle()),
+		Title:      sanitize.Title(pr.GetTitle()),
 		State:      pr.GetState(),
 		HTMLURL:    pr.GetHTMLURL(),
 		Repository: pullRequestRepositoryFullName(pr),
@@ -1353,7 +1353,7 @@ func convertDraftIssueToMinimalProjectItemContent(draftIssue *github.ProjectV2Dr
 	m := &MinimalProjectItemContent{
 		ID:        draftIssue.GetID(),
 		NodeID:    draftIssue.GetNodeID(),
-		Title:     sanitize.Sanitize(draftIssue.GetTitle()),
+		Title:     sanitize.Title(draftIssue.GetTitle()),
 		CreatedAt: formatProjectTimestamp(draftIssue.CreatedAt),
 		UpdatedAt: formatProjectTimestamp(draftIssue.UpdatedAt),
 	}
@@ -1612,7 +1612,7 @@ func minimalProjectPullRequestRefFromPullRequest(pr *github.PullRequest) minimal
 	}
 	return minimalProjectPullRequestRef{
 		Number:     pr.GetNumber(),
-		Title:      sanitize.Sanitize(pr.GetTitle()),
+		Title:      sanitize.Title(pr.GetTitle()),
 		State:      pr.GetState(),
 		HTMLURL:    pr.GetHTMLURL(),
 		Repository: pullRequestRepositoryFullName(pr),
@@ -1634,7 +1634,7 @@ func minimalProjectPullRequestRefFromMap(value map[string]any) minimalProjectPul
 
 	return minimalProjectPullRequestRef{
 		Number:     intFromAny(value["number"]),
-		Title:      sanitize.Sanitize(stringFromMap(value, "title")),
+		Title:      sanitize.Title(stringFromMap(value, "title")),
 		State:      stringFromMap(value, "state"),
 		HTMLURL:    htmlURL,
 		Repository: repository,
@@ -2038,7 +2038,7 @@ func convertToMinimalRelease(release *github.RepositoryRelease) MinimalRelease {
 	m := MinimalRelease{
 		ID:         release.GetID(),
 		TagName:    release.GetTagName(),
-		Name:       sanitize.Sanitize(release.GetName()),
+		Name:       sanitize.Title(release.GetName()),
 		Body:       sanitize.Sanitize(release.GetBody()),
 		HTMLURL:    release.GetHTMLURL(),
 		Prerelease: release.GetPrerelease(),

pkg/github/repositories.go

@@ -2981,7 +2981,7 @@ func GetFileBlame(t translations.TranslationHelperFunc) inventory.ServerTool {
 					SHA: sha,
 					// Sanitized after truncation so the headline is cut at the author's real
 					// first line break rather than one introduced by sanitization.
-					MessageHeadline: sanitize.Sanitize(headline),
+					MessageHeadline: sanitize.Title(headline),
 					CommittedDate:   r.Commit.CommittedDate.Format("2006-01-02T15:04:05Z"),
 					Author: BlameAuthor{
 						Name:  string(r.Commit.Author.Name),

pkg/github/sanitize_coverage_test.go

@@ -257,6 +257,111 @@ func Test_SearchIssueResult_SanitizesTitleAndBody(t *testing.T) {
 	assert.Equal(t, sanitizedText, decoded.Body)
 }
 
+func Test_MinimalConverters_TitlePreservesVisibleText(t *testing.T) {
+	title := "[bug] can't add a connection to toolkits in desktop app"
+
+	tests := []struct {
+		name string
+		got  func() string
+	}{
+		{
+			name: "issue title (REST)",
+			got: func() string {
+				return convertToMinimalIssue(&github.Issue{Title: github.Ptr(title)}).Title
+			},
+		},
+		{
+			name: "issue title (GraphQL)",
+			got: func() string {
+				return fragmentWithoutFieldValuesToMinimalIssue(issueFragmentWithoutFieldValues{
+					Title: githubv4.String(title),
+				}).Title
+			},
+		},
+		{
+			name: "pull request title",
+			got: func() string {
+				return convertToMinimalPullRequest(&github.PullRequest{Title: github.Ptr(title)}).Title
+			},
+		},
+		{
+			name: "release name",
+			got: func() string {
+				return convertToMinimalRelease(&github.RepositoryRelease{Name: github.Ptr(title)}).Name
+			},
+		},
+		{
+			name: "project item content title (issue)",
+			got: func() string {
+				return convertIssueToMinimalProjectItemContent(&github.Issue{Title: github.Ptr(title)}).Title
+			},
+		},
+		{
+			name: "project item content title (pull request)",
+			got: func() string {
+				return convertPullRequestToMinimalProjectItemContent(&github.PullRequest{Title: github.Ptr(title)}).Title
+			},
+		},
+		{
+			name: "project item content title (draft issue)",
+			got: func() string {
+				return convertDraftIssueToMinimalProjectItemContent(&github.ProjectV2DraftIssue{Title: github.Ptr(title)}).Title
+			},
+		},
+		{
+			name: "project pull request ref title (from *github.PullRequest)",
+			got: func() string {
+				return minimalProjectPullRequestRefFromPullRequest(&github.PullRequest{Title: github.Ptr(title)}).Title
+			},
+		},
+		{
+			name: "project pull request ref title (from map)",
+			got: func() string {
+				return minimalProjectPullRequestRefFromMap(map[string]any{"title": title}).Title
+			},
+		},
+		{
+			name: "issue ref title (shared constructor)",
+			got: func() string {
+				return newMinimalIssueRef(1, title, "OPEN", "https://github.com/o/r/issues/1", "o/r").Title
+			},
+		},
+		{
+			name: "pull request ref title (shared constructor)",
+			got: func() string {
+				return newMinimalPullRequestRef(1, title, "OPEN", "https://github.com/o/r/pull/1", "o/r").Title
+			},
+		},
+		{
+			name: "issue dependency ref title",
+			got: func() string {
+				return issueToDependencyRef(&github.Issue{Title: github.Ptr(title)}).Title
+			},
+		},
+		{
+			name: "discussion title",
+			got: func() string {
+				discussion := fragmentToDiscussion(NodeFragment{Title: githubv4.String(title)})
+				return discussion.GetTitle()
+			},
+		},
+		{
+			name: "search issue result title",
+			got: func() string {
+				issue := &github.Issue{Title: github.Ptr(title)}
+				sanitizeIssueTitleAndBody(issue)
+				return issue.GetTitle()
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, title, tt.got())
+		})
+	}
+}
+
 // Test_SanitizeIssueTitleAndBody exercises the shared helper directly, including its nil-safety,
 // since it backs both search_issues and search_pull_requests.
 func Test_SanitizeIssueTitleAndBody(t *testing.T) {

pkg/sanitize/sanitize.go

@@ -36,6 +36,45 @@ func Sanitize(input string) string {
 	return FilterCodeFenceMetadata(FilterInvisibleCharacters(normalized))
 }
 
+// Title sanitizes short metadata fields such as issue and pull request titles.
+// It applies the same HTML and invisible-character policy as Sanitize, then
+// restores the punctuation that policy HTML-escapes so visible characters
+// remain as themselves (for example, "can't" instead of "can't").
+//
+// Angle brackets stay escaped. Decoding < / > would reconstitute markup
+// from entity-encoded tags, including nested < payloads.
+func Title(input string) string {
+	return restoreVisiblePunctuation(Sanitize(input))
+}
+
+// visiblePunctuationUnescaper inverts html.EscapeString for apostrophe, quote,
+// and ampersand only. It must not include < or >.
+var visiblePunctuationUnescaper = strings.NewReplacer(
+	"'", "'",
+	""", `"`,
+	""", `"`,
+	"'", "'",
+	"&", "&",
+)
+
+func restoreVisiblePunctuation(input string) string {
+	if !strings.Contains(input, "&") {
+		return input
+	}
+	out := input
+	// Peel stacked & prefixes (' → ' → ') without ever
+	// turning < / > into angle brackets. Each Replace shortens the
+	// string or is a no-op, so this is bounded by len(input).
+	for range len(input) {
+		next := visiblePunctuationUnescaper.Replace(out)
+		if next == out {
+			return out
+		}
+		out = next
+	}
+	return out
+}
+
 // FilterInvisibleCharacters removes invisible or control characters that should not appear
 // in user-facing titles or bodies. This includes:
 // - Unicode tag characters: U+E0001, U+E0020–U+E007F