Fix character length calculation issue

VERSION

@@ -1 +1 @@
-4.4.4
+4.4.5

internal/toolcall/toolcalls_dsml.go

@@ -17,11 +17,10 @@ func rewriteDSMLToolMarkupOutsideIgnored(text string) string {
 	if text == "" {
 		return ""
 	}
-	lower := strings.ToLower(text)
 	var b strings.Builder
 	b.Grow(len(text))
 	for i := 0; i < len(text); {
-		next, advanced, blocked := skipXMLIgnoredSection(text, lower, i)
+		next, advanced, blocked := skipXMLIgnoredSection(text, i)
 		if blocked {
 			b.WriteString(text[i:])
 			break

internal/toolcall/toolcalls_parse_markup.go

@@ -144,7 +144,7 @@ func findXMLStartTagOutsideCDATA(text, tag string, from int) (start, bodyStart i
 	lower := strings.ToLower(text)
 	target := "<" + strings.ToLower(tag)
 	for i := maxInt(from, 0); i < len(text); {
-		next, advanced, blocked := skipXMLIgnoredSection(text, lower, i)
+		next, advanced, blocked := skipXMLIgnoredSection(text, i)
 		if blocked {
 			return -1, -1, "", false
 		}
@@ -170,7 +170,7 @@ func findMatchingXMLEndTagOutsideCDATA(text, tag string, from int) (closeStart,
 	closeTarget := "</" + strings.ToLower(tag)
 	depth := 1
 	for i := maxInt(from, 0); i < len(text); {
-		next, advanced, blocked := skipXMLIgnoredSection(text, lower, i)
+		next, advanced, blocked := skipXMLIgnoredSection(text, i)
 		if blocked {
 			return -1, -1, false
 		}
@@ -206,16 +206,20 @@ func findMatchingXMLEndTagOutsideCDATA(text, tag string, from int) (closeStart,
 	return -1, -1, false
 }
 
-func skipXMLIgnoredSection(text, lower string, i int) (next int, advanced bool, blocked bool) {
+func skipXMLIgnoredSection(text string, i int) (next int, advanced bool, blocked bool) {
+	if i < 0 || i >= len(text) {
+		return i, false, false
+	}
+	tail := strings.ToLower(text[i:])
 	switch {
-	case strings.HasPrefix(lower[i:], "<![cdata["):
-		end := findToolCDATAEnd(text, lower, i+len("<![cdata["))
+	case strings.HasPrefix(tail, "<![cdata["):
+		end := findToolCDATAEnd(text, i+len("<![cdata["))
 		if end < 0 {
 			return 0, false, true
 		}
 		return end + len("]]>"), true, false
-	case strings.HasPrefix(lower[i:], "<!--"):
-		end := strings.Index(lower[i+len("<!--"):], "-->")
+	case strings.HasPrefix(tail, "<!--"):
+		end := strings.Index(tail[len("<!--"):], "-->")
 		if end < 0 {
 			return 0, false, true
 		}
@@ -225,14 +229,14 @@ func skipXMLIgnoredSection(text, lower string, i int) (next int, advanced bool,
 	}
 }
 
-func findToolCDATAEnd(text, lower string, from int) int {
-	if from < 0 || from > len(text) {
+func findToolCDATAEnd(text string, from int) int {
+	if from < 0 || from >= len(text) {
 		return -1
 	}
 	const closeMarker = "]]>"
 	firstNonFenceEnd := -1
 	for searchFrom := from; searchFrom < len(text); {
-		rel := strings.Index(lower[searchFrom:], closeMarker)
+		rel := strings.Index(text[searchFrom:], closeMarker)
 		if rel < 0 {
 			break
 		}
@@ -241,27 +245,28 @@ func findToolCDATAEnd(text, lower string, from int) int {
 		if cdataOffsetIsInsideMarkdownFence(text[from:end]) {
 			continue
 		}
+		if cdataEndLooksStructural(text, searchFrom) {
+			return end
+		}
 		if firstNonFenceEnd < 0 {
 			firstNonFenceEnd = end
 		}
-		if cdataEndLooksStructural(lower, searchFrom) {
-			return end
-		}
 	}
 	return firstNonFenceEnd
 }
 
-func cdataEndLooksStructural(lower string, after int) bool {
-	for after < len(lower) {
-		switch lower[after] {
-		case ' ', '\t', '\r', '\n':
+func cdataEndLooksStructural(text string, after int) bool {
+	for after < len(text) {
+		switch {
+		case text[after] == ' ' || text[after] == '\t' || text[after] == '\r' || text[after] == '\n':
 			after++
-			continue
+		case after+1 < len(text) && text[after] == '<' && text[after+1] == '/':
+			return true
 		default:
+			return false
 		}
-		break
 	}
-	return strings.HasPrefix(lower[after:], "</")
+	return false
 }
 
 func cdataOffsetIsInsideMarkdownFence(fragment string) bool {

internal/toolcall/toolcalls_scan.go

@@ -28,9 +28,8 @@ type ToolMarkupTag struct {
 }
 
 func ContainsToolMarkupSyntaxOutsideIgnored(text string) (hasDSML, hasCanonical bool) {
-	lower := strings.ToLower(text)
 	for i := 0; i < len(text); {
-		next, advanced, blocked := skipXMLIgnoredSection(text, lower, i)
+		next, advanced, blocked := skipXMLIgnoredSection(text, i)
 		if blocked {
 			return hasDSML, hasCanonical
 		}
@@ -56,9 +55,8 @@ func ContainsToolMarkupSyntaxOutsideIgnored(text string) (hasDSML, hasCanonical
 }
 
 func ContainsToolCallWrapperSyntaxOutsideIgnored(text string) (hasDSML, hasCanonical bool) {
-	lower := strings.ToLower(text)
 	for i := 0; i < len(text); {
-		next, advanced, blocked := skipXMLIgnoredSection(text, lower, i)
+		next, advanced, blocked := skipXMLIgnoredSection(text, i)
 		if blocked {
 			return hasDSML, hasCanonical
 		}
@@ -88,9 +86,8 @@ func ContainsToolCallWrapperSyntaxOutsideIgnored(text string) (hasDSML, hasCanon
 }
 
 func FindToolMarkupTagOutsideIgnored(text string, start int) (ToolMarkupTag, bool) {
-	lower := strings.ToLower(text)
 	for i := maxInt(start, 0); i < len(text); {
-		next, advanced, blocked := skipXMLIgnoredSection(text, lower, i)
+		next, advanced, blocked := skipXMLIgnoredSection(text, i)
 		if blocked {
 			return ToolMarkupTag{}, false
 		}
@@ -107,7 +104,7 @@ func FindToolMarkupTagOutsideIgnored(text string, start int) (ToolMarkupTag, boo
 }
 
 func FindMatchingToolMarkupClose(text string, open ToolMarkupTag) (ToolMarkupTag, bool) {
-	if text == "" || open.Name == "" || open.Closing {
+	if text == "" || open.Name == "" || open.Closing || open.End >= len(text) {
 		return ToolMarkupTag{}, false
 	}
 	depth := 1

internal/toolcall/toolcalls_test.go

@@ -892,3 +892,107 @@ func TestParseToolCallsSkipsProseMentionOfSameWrapperVariant(t *testing.T) {
 		t.Fatalf("expected command to parse, got %q", got)
 	}
 }
+
+func TestTurkishILowercaseMapping(t *testing.T) {
+	tests := []struct {
+		name     string
+		text     string
+		start    int
+		wantOk   bool
+		wantName string
+	}{
+		{"turkish_i_at_name_start", "İ<tool>", 0, false, ""},
+		{"turkish_i_at_name_end", "<toolİ>", 0, false, ""},
+		{"turkish_i_before_tag", "İ<tool>", 0, false, ""},
+		{"normal_tool_calls", "<tool_calls>", 0, true, "tool_calls"},
+		{"normal_invoke", "<invoke name=\"test\">", 0, true, "invoke"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, ok := FindToolMarkupTagOutsideIgnored(tt.text, tt.start)
+			if ok != tt.wantOk {
+				t.Errorf("FindToolMarkupTagOutsideIgnored(%q, %d) ok = %v, want %v", tt.text, tt.start, ok, tt.wantOk)
+				return
+			}
+			if ok && got.Name != tt.wantName {
+				t.Errorf("FindToolMarkupTagOutsideIgnored(%q, %d) name = %q, want %q", tt.text, tt.start, got.Name, tt.wantName)
+			}
+		})
+	}
+}
+
+func TestSkipXMLIgnoredSectionBoundaryConditions(t *testing.T) {
+	text := "hello"
+
+	tests := []struct {
+		name     string
+		i        int
+		wantNext int
+		wantAdv  bool
+		wantBlk  bool
+	}{
+		{"valid_index", 2, 2, false, false},
+		{"at_end_equal_len", 5, 5, false, false},
+		{"beyond_end", 6, 6, false, false},
+		{"negative", -1, -1, false, false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			next, adv, blk := skipXMLIgnoredSection(text, tt.i)
+			if next != tt.wantNext || adv != tt.wantAdv || blk != tt.wantBlk {
+				t.Errorf("skipXMLIgnoredSection(%q, %d) = (%d, %v, %v), want (%d, %v, %v)",
+					text, tt.i, next, adv, blk, tt.wantNext, tt.wantAdv, tt.wantBlk)
+			}
+		})
+	}
+}
+
+func TestFindToolCDATAEndBoundaryConditions(t *testing.T) {
+	text := "<![CDATA[hello]]>"
+
+	tests := []struct {
+		name       string
+		from       int
+		wantResult int
+	}{
+		{"valid", 12, 14},
+		{"at_end", 17, -1},
+		{"beyond_end", 18, -1},
+		{"negative", -1, -1},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := findToolCDATAEnd(text, tt.from)
+			if got != tt.wantResult {
+				t.Errorf("findToolCDATAEnd(%q, %d) = %d, want %d",
+					text, tt.from, got, tt.wantResult)
+			}
+		})
+	}
+}
+
+func TestFindMatchingToolMarkupCloseBoundaryConditions(t *testing.T) {
+	tests := []struct {
+		name   string
+		text   string
+		open   ToolMarkupTag
+		wantOk bool
+	}{
+		{"empty_text", "", ToolMarkupTag{Name: "tool_calls", End: 0}, false},
+		{"open_end_beyond_text", "hello", ToolMarkupTag{Name: "tool_calls", End: 100}, false},
+		{"open_end_equals_len", "hello", ToolMarkupTag{Name: "tool_calls", End: 5}, false},
+		{"valid_simple", "<tool_calls></tool_calls>", ToolMarkupTag{Name: "tool_calls", End: 11}, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, ok := FindMatchingToolMarkupClose(tt.text, tt.open)
+			if ok != tt.wantOk {
+				t.Errorf("FindMatchingToolMarkupClose(%q, %+v) ok = %v, want %v", tt.text, tt.open, ok, tt.wantOk)
+			}
+		})
+	}
+}