[libclang] Indexing API: fill the objc category info for a category implementation and
do not crash if no client container is registered for a declaration context.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144765 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/c-index-test/c-index-test.c b/tools/c-index-test/c-index-test.c
index 56b5552..c479278 100644
--- a/tools/c-index-test/c-index-test.c
+++ b/tools/c-index-test/c-index-test.c
@@ -1610,7 +1610,10 @@
 }
 
 static void printCXIndexContainer(CXIdxClientContainer container) {
-  printf("[%s]", (const char *)container);
+  if (!container)
+    printf("[<<NULL>>]");
+  else
+    printf("[%s]", (const char *)container);
 }
 
 static const char *getEntityKindString(CXIdxEntityKind kind) {