add condition to skip unmapping for internally allocated host memory. this should fix map_unmap_counting UMat test.

modules/core/src/ocl.cpp

@@ -4572,13 +4572,16 @@ public:
                     else
                     {
                         // CL_MEM_USE_HOST_PTR (nothing is required) and OTHER cases
-                        cl_int retval = 0;
-                        void* data = clEnqueueMapBuffer(q, (cl_mem)u->handle, CL_TRUE,
-                                                        (CL_MAP_READ | CL_MAP_WRITE),
-                                                        0, u->size, 0, 0, 0, &retval);
-                        CV_OclDbgAssert(retval == CL_SUCCESS);
-                        CV_OclDbgAssert(clEnqueueUnmapMemObject(q, (cl_mem)u->handle, data, 0, 0, 0) == CL_SUCCESS);
-                        CV_OclDbgAssert(clFinish(q) == CL_SUCCESS);
+                        if (u->flags & UMatData::USER_ALLOCATED)
+                        {
+                            cl_int retval = 0;
+                            void* data = clEnqueueMapBuffer(q, (cl_mem)u->handle, CL_TRUE,
+                                (CL_MAP_READ | CL_MAP_WRITE),
+                                0, u->size, 0, 0, 0, &retval);
+                            CV_OclDbgAssert(retval == CL_SUCCESS);
+                            CV_OclDbgAssert(clEnqueueUnmapMemObject(q, (cl_mem)u->handle, data, 0, 0, 0) == CL_SUCCESS);
+                            CV_OclDbgAssert(clFinish(q) == CL_SUCCESS);
+                        }
                     }
                 }
                 u->markHostCopyObsolete(false);