Fix (and add test case for) a bug where objc_allocateClassPair() failed if the

superclass had not yet been loaded.

Test/AllocatePair.m

@@ -0,0 +1,38 @@
+#include "Test.h"
+#include <objc/runtime.h>
+#include <stdio.h>
+
+// Regression test for a bug where allocating a class as a subclass of an
+// unresolved class failed.
+
+static int loaded;
+
+static void load(Class self, SEL _cmd)
+{
+	loaded++;
+}
+
+int main()
+{
+	Class a, b, c, d, e;
+
+	a = objc_allocateClassPair([Test class], "A", 0);
+	objc_registerClassPair(a);
+
+	b = objc_allocateClassPair(a, "B", 0);
+	class_addMethod(object_getClass(b), @selector(load), (IMP)load, "@:");
+	objc_registerClassPair(b);
+	class_getSuperclass(b);
+
+	c = objc_allocateClassPair(b, "C", 0);
+	objc_registerClassPair(c);
+	d = objc_allocateClassPair(c, "D", 0);
+	objc_registerClassPair(d);
+	e = objc_allocateClassPair(d, "E", 0);
+	objc_registerClassPair(e);
+	assert(loaded == 0);
+
+	return 0;
+}
+
+

Test/CMakeLists.txt

@@ -5,6 +5,7 @@
 
 # List of single-file tests.
 set(TESTS
+	AllocatePair.m
 	BlockImpTest.m
 	BoxedForeignException.m
 	ExceptionTest.m

class_table.c

@@ -486,7 +486,7 @@ Class class_getSuperclass(Class cls)
 	if (Nil == cls) { return Nil; }
 	if (!objc_test_class_flag(cls, objc_class_flag_resolved))
 	{
-		objc_resolve_class(cls);
+		return objc_getClass((const char*)cls->super_class);
 	}
 	return cls->super_class;
 }

runtime.c

@@ -698,8 +698,18 @@ Class objc_allocateClassPair(Class superclass, const char *name, size_t extraByt
 		// Initialize the metaclass
 		// Set the meta-metaclass pointer to the name.  The runtime will fix this
 		// in objc_resolve_class().
-		metaClass->isa = (Class)superclass->isa->isa->name;
-		metaClass->super_class = superclass->isa;
+		// If the superclass is not yet resolved, then we need to look it up
+		// via the class table.
+		if (!objc_test_class_flag(superclass, objc_class_flag_resolved))
+		{
+			metaClass->super_class = (Class)objc_getClass((char*)superclass->super_class);
+			metaClass->isa = (Class)metaClass->super_class->isa->name;
+		}
+		else
+		{
+			metaClass->isa = (Class)superclass->isa->isa->name;
+			metaClass->super_class = superclass->isa;
+		}
 	}
 	metaClass->name = strdup(name);
 	metaClass->info = objc_class_flag_meta | objc_class_flag_user_created |