Revert "load now does not modify the incomming data"

This reverts commit 2126e9fee1.
we judge this to be too big a change for stable, keeping in devel
we may still add part or all back to stable in the future.

lib/ansible/parsing/dataloader.py

@@ -20,6 +20,7 @@ from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
 import copy
+import json
 import os
 import stat
 import subprocess
@@ -73,24 +74,30 @@ class DataLoader():
         a JSON or YAML string.
         '''
 
-        # YAML parser will take JSON as it is a subset.
-        if isinstance(data, AnsibleUnicode):
-            # The PyYAML's libyaml bindings use PyUnicode_CheckExact so
-            # they are unable to cope with our subclass.
-            # Unwrap and re-wrap the unicode so we can keep track of line
-            # numbers
-            in_data = text_type(data)
-        else:
-            in_data = data
         try:
-            new_data = self._safe_load(in_data, file_name=file_name)
-        except YAMLError as yaml_exc:
-            self._handle_error(yaml_exc, file_name, show_content)
-
-        if isinstance(data, AnsibleUnicode):
-            new_data = AnsibleUnicode(new_data)
-            new_data.ansible_pos = data.ansible_pos
-        return new_data
+            # we first try to load this data as JSON
+            return json.loads(data)
+        except:
+            # if loading JSON failed for any reason, we go ahead
+            # and try to parse it as YAML instead
+
+            if isinstance(data, AnsibleUnicode):
+                # The PyYAML's libyaml bindings use PyUnicode_CheckExact so
+                # they are unable to cope with our subclass.
+                # Unwrap and re-wrap the unicode so we can keep track of line
+                # numbers
+                new_data = text_type(data)
+            else:
+                new_data = data
+            try:
+                new_data = self._safe_load(new_data, file_name=file_name)
+            except YAMLError as yaml_exc:
+                self._handle_error(yaml_exc, file_name, show_content)
+
+            if isinstance(data, AnsibleUnicode):
+                new_data = AnsibleUnicode(new_data)
+                new_data.ansible_pos = data.ansible_pos
+            return new_data
 
     def load_from_file(self, file_name):
         ''' Loads data from a file, which can contain either JSON or YAML.  '''