Fixes #87: Do not cache search results if regular expression contains \G

spec/onig-scanner-spec.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const OnigScanner = require('..').OnigScanner
+const OnigString = require('..').OnigString;
 
 describe('OnigScanner', () => {
   describe('::findNextMatchSync', () => {
@@ -113,6 +114,18 @@ describe('OnigScanner', () => {
     })
   )
 
+  describe('when a regular expression contains \\G', () =>
+    it('it does not get cached', () => {
+      let str = new OnigString('first-and-second');
+      let scanner = new OnigScanner(['\\G-and'])
+      let match = scanner.findNextMatchSync(str, 0)
+      expect(match).toEqual(null)
+
+      match = scanner.findNextMatchSync(str, 5)
+      expect(match.captureIndices).toEqual([{index: 0, start: 5, end: 9, length: 4}])
+    })
+  )
+
   describe('::findNextMatch', () => {
     let matchCallback
 

src/onig-reg-exp.cc

@@ -10,6 +10,17 @@ OnigRegExp::OnigRegExp(const string& source)
   lastSearchPosition = -1;
   lastSearchResult = NULL;
 
+  hasGAnchor = false;
+  for (size_t pos = 0, len = source.size(); pos < len; pos++) {
+    if (source[pos] == '\\' && pos + 1 < len) {
+      if (source[pos + 1] == 'G') {
+        hasGAnchor = true;
+        break;
+      }
+      pos++;
+    }
+  }
+
   OnigErrorInfo error;
   const UChar* sourceData = (const UChar*)source.data();
   int status = onig_new(&regex_, sourceData, sourceData + source.length(),
@@ -28,6 +39,12 @@ OnigRegExp::~OnigRegExp() {
 }
 
 shared_ptr<OnigResult> OnigRegExp::Search(OnigString* str, int position) {
+  if (hasGAnchor) {
+    // Should not use caching, because the regular expression
+    // targets the current search position (\G)
+    return Search(str->utf8_value(), position, str->utf8_length());
+  }
+
   if (lastSearchStrUniqueId == str->uniqueId() && lastSearchPosition <= position) {
     if (lastSearchResult == NULL || lastSearchResult->LocationAt(0) >= position) {
       return lastSearchResult;

src/onig-reg-exp.h

@@ -26,6 +26,7 @@ class OnigRegExp {
   string source_;
   regex_t* regex_;
 
+  bool hasGAnchor;
   int lastSearchStrUniqueId;
   int lastSearchPosition;
   shared_ptr<OnigResult> lastSearchResult;