buffer: fix UCS2 indexOf for odd buffer length

addaleax · evanlucas · commit 9cd14ced095b · 2016-05-17T08:03:31.000-05:00
Fix `buffer.indexOf` for the case that the haystack has odd length and the needle is not found in it. `StringSearch()` would return the length of the buffer in multiples of `sizeof(uint16_t)`, but checking that against `haystack_length` would not work if the latter one was odd. PR-URL: #6511 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Trevor Norris <trev.norris@gmail.com>
diff --git a/src/node_buffer.cc b/src/node_buffer.cc
@@ -994,7 +994,9 @@ void IndexOfString(const FunctionCallbackInfo<Value>& args) {
   bool is_forward = args[4]->IsTrue();
 
   const char* haystack = ts_obj_data;
-  const size_t haystack_length = ts_obj_length;
+  // Round down to the nearest multiple of 2 in case of UCS2.
+  const size_t haystack_length = (enc == UCS2) ?
+      ts_obj_length &~ 1 : ts_obj_length;  // NOLINT(whitespace/operators)
 
   const size_t needle_length =
       StringBytes::Size(args.GetIsolate(), needle, enc);
diff --git a/test/parallel/test-buffer-indexof.js b/test/parallel/test-buffer-indexof.js
@@ -228,6 +228,9 @@ assert.strictEqual(Buffer.from('aaaa').indexOf('a'.repeat(4), 'ucs2'), -1);
 assert.strictEqual(Buffer.from('aaaa').indexOf('a'.repeat(4), 'utf8'), 0);
 assert.strictEqual(Buffer.from('aaaa').indexOf('&#20320;&#22909;', 'ucs2'), -1);
 
+// Haystack has odd length, but the needle is UCS2.
+assert.strictEqual(Buffer.from('aaaaa').indexOf('b', 'ucs2'), -1);
+
 {
   // Find substrings in Utf8.
   const lengths = [1, 3, 15];  // Single char, simple and complex.

Original file line number	Diff line number	Diff line change
`@@ -228,6 +228,9 @@ assert.strictEqual(Buffer.from('aaaa').indexOf('a'.repeat(4), 'ucs2'), -1);`
`228`	`228`	`assert.strictEqual(Buffer.from('aaaa').indexOf('a'.repeat(4), 'utf8'), 0);`
`229`	`229`	`assert.strictEqual(Buffer.from('aaaa').indexOf('你好', 'ucs2'), -1);`
`230`	`230`
	`231`	`+// Haystack has odd length, but the needle is UCS2.`
	`232`	`+assert.strictEqual(Buffer.from('aaaaa').indexOf('b', 'ucs2'), -1);`
	`233`	`+`
`231`	`234`	`{`
`232`	`235`	`// Find substrings in Utf8.`
`233`	`236`	`const lengths = [1, 3, 15]; // Single char, simple and complex.`