querystring: fix unescape override

Documentation states that `querystring.unescape` may be overridden to
replace unescaper during parsing. However, the function was only
being used as a fallback for when the native decoder throws (on a
malformed URL). This patch moves the call to the native function and
the try/catch around it into querystring.unescape then has the parser
always invoke it, so that an override will always be used.

Fixes #4055

Reviewed-By: Fedor Indutny <fedor@indutny.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/test/simple/test-querystring.js b/test/simple/test-querystring.js
index 2d86625f32..545c507fc4 100644
--- a/test/simple/test-querystring.js
+++ b/test/simple/test-querystring.js
@@ -229,3 +229,11 @@ assert.equal(0xeb, b[16]);
 assert.equal(0xd8, b[17]);
 assert.equal(0xa2, b[18]);
 assert.equal(0xe6, b[19]);
+
+// test overriding .unescape
+var prevUnescape = qs.unescape;
+qs.unescape = function (str) {
+  return str.replace(/o/g, '_');
+};
+assert.deepEqual(qs.parse('foo=bor'), {f__: 'b_r'});
+qs.unescape = prevUnescape;