Merge pull request #3307 from rogercloud/devel

Fix issue #2245

lib/pure/json.nim

@@ -1074,9 +1074,9 @@ when not defined(js):
     ## for nice error messages.
     var p: JsonParser
     p.open(s, filename)
+    defer: p.close()
     discard getTok(p) # read first token
     result = p.parseJson()
-    p.close()
 
   proc parseJson*(buffer: string): JsonNode =
     ## Parses JSON from `buffer`.
@@ -1203,6 +1203,17 @@ when isMainModule:
   testJson{["c", "d"]} = %true
   assert(testJson["c"]["d"].bval)
 
+  # make sure no memory leek when parsing invalid string
+  let startMemory = getOccupiedMem()
+  for i in 0 .. 10000:
+    try:
+      discard parseJson"""{ invalid"""
+    except:
+      discard
+  # memory diff should less than 2M
+  assert(abs(getOccupiedMem() - startMemory) < 2 * 1024 * 1024)
+
+
   # test `$`
   let stringified = $testJson
   let parsedAgain = parseJson(stringified)