we need this because of one pesky little bug going around (when union is recognized and the dbmses are fingerprinted, for those who don't have proper unescaping false TRUE is recognized in form of retrieved: %27%2B%28SELECT%20CAST...). tested on all major DBMSes.

lib/request/inject.py

@@ -475,12 +475,15 @@ def getValue(expression, blind=True, inband=True, error=True, time=True, fromUse
 
     if value and expected == EXPECTED.BOOL:
         if isinstance(value, basestring):
+            value = value.strip()
             if value.lower() in ("true", "false"):
                 value = bool(value)
             elif value.capitalize() == "None":
                 value = None
+            elif value in ("1", "-1"):
+                value = True
             else:
-                value = value != "0"
+                value = None
         elif isinstance(value, int):
             value = bool(value)
         elif value == [None]: