commit 156161dfcde38b72c55ead02cacff7087c93a4d8
author Thomas Van Lenten <thomasvl@google.com> Wed Jan 03 11:19:53 2018 -0500
committer Thomas Van Lenten <thomasvl@google.com> Wed Jan 03 11:46:03 2018 -0500
tree f2c3f5e9b754514d5cf4422c2959ad6fc1eae03b
parent 8529f2aee33ae793c9ce362a45370b98f675370a

Properly copy maps with string keys but pod values.

Add tests to cover all the common special casing in the runtime code to
ensure things come out correctly.

objectivec/GPBMessage.m

diff --git a/objectivec/GPBMessage.m b/objectivec/GPBMessage.m
index 90485bd..3be20b6 100644
--- a/objectivec/GPBMessage.m
+++ b/objectivec/GPBMessage.m
@@ -969,7 +969,8 @@
               newValue = [value copyWithZone:zone];
             }
           } else {
-            if (field.mapKeyDataType == GPBDataTypeString) {
+            if ((field.mapKeyDataType == GPBDataTypeString) &&
+                GPBFieldDataTypeIsObject(field)) {
               // NSDictionary
               newValue = [value mutableCopyWithZone:zone];
             } else {