From ad16c243cacda5cb4b6aa8901669167cfc192afc Mon Sep 17 00:00:00 2001
From: Jan Solanti <jan.solanti@tuni.fi>
Date: Tue, 3 Mar 2020 14:16:32 +0200
Subject: [PATCH] core(ocl): Don't query image formats when none exist

clGetSupportedImageFormats returns CL_INVALID_VALUE if called with
num_entries 0 and a non-NULL image_formats pointer so let's not do that.
---
 modules/core/src/ocl.cpp | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/modules/core/src/ocl.cpp b/modules/core/src/ocl.cpp
index dbebf02f7f..52533484a0 100644
--- a/modules/core/src/ocl.cpp
+++ b/modules/core/src/ocl.cpp
@@ -6445,16 +6445,19 @@ struct Image2D::Impl
                                                 CL_MEM_OBJECT_IMAGE2D, numFormats,
                                                 NULL, &numFormats);
         CV_OCL_DBG_CHECK_RESULT(err, "clGetSupportedImageFormats(CL_MEM_OBJECT_IMAGE2D, NULL)");
-        AutoBuffer<cl_image_format> formats(numFormats);
-        err = clGetSupportedImageFormats(context, CL_MEM_READ_WRITE,
-                                         CL_MEM_OBJECT_IMAGE2D, numFormats,
-                                         formats.data(), NULL);
-        CV_OCL_DBG_CHECK_RESULT(err, "clGetSupportedImageFormats(CL_MEM_OBJECT_IMAGE2D, formats)");
-        for (cl_uint i = 0; i < numFormats; ++i)
+        if (numFormats > 0)
         {
-            if (!memcmp(&formats[i], &format, sizeof(format)))
+            AutoBuffer<cl_image_format> formats(numFormats);
+            err = clGetSupportedImageFormats(context, CL_MEM_READ_WRITE,
+                                             CL_MEM_OBJECT_IMAGE2D, numFormats,
+                                             formats.data(), NULL);
+            CV_OCL_DBG_CHECK_RESULT(err, "clGetSupportedImageFormats(CL_MEM_OBJECT_IMAGE2D, formats)");
+            for (cl_uint i = 0; i < numFormats; ++i)
             {
-                return true;
+                if (!memcmp(&formats[i], &format, sizeof(format)))
+                {
+                    return true;
+                }
             }
         }
         return false;