Fix ktx_strncasecmp (#741)

Fixes #740.

lib/mkvkformatfiles

@@ -183,6 +183,8 @@ END {
     begin_str2vk = begin_str2vk "        ++us2;\n"
     begin_str2vk = begin_str2vk "        --length;\n"
     begin_str2vk = begin_str2vk "    }\n"
+    begin_str2vk = begin_str2vk "    if (length == 0)\n"
+    begin_str2vk = begin_str2vk "        return 0;\n"
     begin_str2vk = begin_str2vk "    return tolower(*us1) - tolower(*us2);\n"
     begin_str2vk = begin_str2vk "}\n"
     begin_str2vk = begin_str2vk "\n"

lib/vkformat_str.c

@@ -594,6 +594,8 @@ static int ktx_strncasecmp(const char* s1, const char* s2, int length) {
         ++us2;
         --length;
     }
+    if (length == 0)
+        return 0;
     return tolower(*us1) - tolower(*us2);
 }
 

tests/tests.cmake

@@ -33,6 +33,7 @@ add_subdirectory(streamtests)
 add_executable( unittests
     unittests/image_unittests.cc
     unittests/test_fragment_uri.cc
+    unittests/test_string_to_vkformat.cc
     unittests/unittests.cc
     unittests/wthelper.h
     tests.cmake

tests/unittests/test_fragment_uri.cc

@@ -1,10 +1,8 @@
 /* -*- tab-width: 4; -*- */
 /* vi: set sw=2 ts=4 expandtab: */
-
-/*
- * Copyright 2010-2020 Mark Callow.
- * SPDX-License-Identifier: Apache-2.0
- */
+// Copyright 2022-2023 The Khronos Group Inc.
+// Copyright 2022-2023 RasterGrid Kft.
+// SPDX-License-Identifier: Apache-2.0
 
 #include <ktx/fragment_uri.h>
 #include "gtest/gtest.h"

tests/unittests/test_string_to_vkformat.cc

@@ -0,0 +1,54 @@
+/* -*- tab-width: 4; -*- */
+/* vi: set sw=2 ts=4 expandtab: */
+// Copyright 2022-2023 The Khronos Group Inc.
+// Copyright 2022-2023 RasterGrid Kft.
+// SPDX-License-Identifier: Apache-2.0
+
+#include "vkformat_enum.h"
+#include "gtest/gtest.h"
+
+
+extern "C" {
+    VkFormat stringToVkFormat(const char* str);
+}
+
+// -------------------------------------------------------------------------------------------------
+
+class StringToVkFormatTest : public ::testing::Test {
+protected:
+    StringToVkFormatTest() {}
+};
+
+// -------------------------------------------------------------------------------------------------
+
+namespace {
+
+TEST_F(StringToVkFormatTest, stringToVkFormat) {
+    EXPECT_EQ(stringToVkFormat("UNDEFINED"), VK_FORMAT_UNDEFINED);
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_UNDEFINED"), VK_FORMAT_UNDEFINED);
+    EXPECT_EQ(stringToVkFormat("Not a format"), VK_FORMAT_UNDEFINED);
+
+    EXPECT_EQ(stringToVkFormat("R4G4_UNORM_PACK8"), VK_FORMAT_R4G4_UNORM_PACK8);
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_R4G4_UNORM_PACK8"), VK_FORMAT_R4G4_UNORM_PACK8);
+
+    EXPECT_EQ(stringToVkFormat("R8G8B8_UNORM"), VK_FORMAT_R8G8B8_UNORM);
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_R8G8B8_UNORM"), VK_FORMAT_R8G8B8_UNORM);
+    EXPECT_EQ(stringToVkFormat("R8G8B8_SNORM"), VK_FORMAT_R8G8B8_SNORM);
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_R8G8B8_SNORM"), VK_FORMAT_R8G8B8_SNORM);
+
+    EXPECT_EQ(stringToVkFormat("ASTC_6x6_UNORM_BLOCK"), VK_FORMAT_ASTC_6x6_UNORM_BLOCK);
+    EXPECT_EQ(stringToVkFormat("ASTC_6X6_UNORM_BLOCK"), VK_FORMAT_ASTC_6x6_UNORM_BLOCK);
+    EXPECT_EQ(stringToVkFormat("astc_6x6_unorm_block"), VK_FORMAT_ASTC_6x6_UNORM_BLOCK);
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_ASTC_6x6_UNORM_BLOCK"), VK_FORMAT_ASTC_6x6_UNORM_BLOCK);
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_ASTC_6X6_UNORM_BLOCK"), VK_FORMAT_ASTC_6x6_UNORM_BLOCK);
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_ASTC_6X6_UNORM_BLOCK"), VK_FORMAT_ASTC_6x6_UNORM_BLOCK);
+    EXPECT_EQ(stringToVkFormat("vk_format_astc_6x6_unorm_block"), VK_FORMAT_ASTC_6x6_UNORM_BLOCK);
+
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_ASTC_6x6_UNORM"), VK_FORMAT_UNDEFINED);
+    EXPECT_EQ(stringToVkFormat("VK_FORMAT_ASTC_6x6_UNORM_BLOC"), VK_FORMAT_UNDEFINED);
+    EXPECT_EQ(stringToVkFormat("K_FORMAT_ASTC_6x6_UNORM_BLOCK"), VK_FORMAT_UNDEFINED);
+    EXPECT_EQ(stringToVkFormat("_ASTC_6x6_UNORM_BLOCK"), VK_FORMAT_UNDEFINED);
+    EXPECT_EQ(stringToVkFormat("STC_6x6_UNORM_BLOCK"), VK_FORMAT_UNDEFINED);
+}
+
+} // namespace