Skip abutting empty replace_all matches

Author: mgomes

vibes/builtins.go

@@ -499,11 +499,23 @@ func regexReplaceAllWithLimit(re *regexp.Regexp, text string, replacement string
 	out := make([]byte, 0, len(text))
 	lastAppended := 0
 	searchStart := 0
+	lastMatchEnd := -1
 	for searchStart <= len(text) {
 		loc, found := nextRegexReplaceAllSubmatchIndex(re, text, searchStart)
 		if !found {
 			break
 		}
+		if loc[0] == loc[1] && loc[0] == lastMatchEnd {
+			if loc[0] >= len(text) {
+				break
+			}
+			_, size := utf8.DecodeRuneInString(text[loc[0]:])
+			if size == 0 {
+				size = 1
+			}
+			searchStart = loc[0] + size
+			continue
+		}
 
 		segmentLen := loc[0] - lastAppended
 		if len(out) > maxRegexInputBytes-segmentLen {
@@ -515,6 +527,7 @@ func regexReplaceAllWithLimit(re *regexp.Regexp, text string, replacement string
 			return "", fmt.Errorf("%s output exceeds limit %d bytes", method, maxRegexInputBytes)
 		}
 		lastAppended = loc[1]
+		lastMatchEnd = loc[1]
 
 		if loc[1] > loc[0] {
 			searchStart = loc[1]

vibes/runtime_test.go

@@ -1956,6 +1956,7 @@ func TestRegexBuiltins(t *testing.T) {
 	        replace_all: Regex.replace_all("ID-12 ID-34", "ID-[0-9]+", "X"),
 	        replace_all_anchor: Regex.replace_all("abc", "^", "X"),
 	        replace_all_boundary: Regex.replace_all("ab", "\\b", "X"),
+	        replace_all_abutting_empty: Regex.replace_all("aa", "aa|", "X"),
 	        replace_capture: Regex.replace("ID-12 ID-34", "ID-([0-9]+)", "X-$1"),
 	        replace_boundary: Regex.replace("ab", "\\Bb", "X")
 	      }
@@ -1992,6 +1993,9 @@ func TestRegexBuiltins(t *testing.T) {
 	if !out["replace_all_boundary"].Equal(NewString("XabX")) {
 		t.Fatalf("replace_all_boundary mismatch: %v", out["replace_all_boundary"])
 	}
+	if !out["replace_all_abutting_empty"].Equal(NewString("X")) {
+		t.Fatalf("replace_all_abutting_empty mismatch: %v", out["replace_all_abutting_empty"])
+	}
 	if !out["replace_capture"].Equal(NewString("X-12 ID-34")) {
 		t.Fatalf("replace_capture mismatch: %v", out["replace_capture"])
 	}