Add autotest/cpp/test_deferred_plugin.cpp

autotest/cpp/CMakeLists.txt

@@ -294,7 +294,9 @@ set(QUICKTEST_LIST
     test-multi-threaded-writing
     test-destroy
     test-bug1488
-    test-log)
+    test-log
+    test-deferred-plugin
+)
 
 gdal_gtest_target(testcopywords test-copy-words testcopywords.cpp)
 gdal_gtest_target(testclosedondestroydm test-closed-on-destroy-DM testclosedondestroydm.cpp)
@@ -308,6 +310,11 @@ gdal_autotest_target(test_include_from_c_file test-include-from-C-file test_incl
 gdal_autotest_target(test_c_include_from_cpp_file test-C-include-from-CPP-file test_c_include_from_cpp_file.cpp "")
 gdal_gtest_target(bug1488 test-bug1488 bug1488.cpp)
 gdal_gtest_target(testlog test-log testlog.cpp)
+gdal_gtest_target(test_deferred_plugin test-deferred-plugin test_deferred_plugin.cpp)
+
+if (GDAL_ENABLE_DRIVER_JPEG_PLUGIN)
+    target_compile_definitions(test_deferred_plugin PRIVATE -DJPEG_PLUGIN)
+endif()
 
 if (UNIX)
   list(APPEND QUICKTEST_LIST test-osr-set-proj-search-paths)

autotest/cpp/test_deferred_plugin.cpp

@@ -0,0 +1,83 @@
+/******************************************************************************
+ * $Id$
+ *
+ * Project:  GDAL
+ * Purpose:  Test deferred plugin loading
+ * Author:   Even Rouault, even.rouault at spatialys.com
+ *
+ ******************************************************************************
+ * Copyright (c) 2023, Even Rouault <even.rouault at spatialys.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ ****************************************************************************/
+
+#include "gdal_priv.h"
+
+#include "gtest_include.h"
+
+#include "test_data.h"
+
+namespace
+{
+
+// ---------------------------------------------------------------------------
+
+TEST(test_deferredplugin, test_missing)
+{
+#ifdef JPEG_PLUGIN
+    CPLSetConfigOption("GDAL_DRIVER_PATH", "/i/do_not_exist");
+    GDALAllRegister();
+    CPLSetConfigOption("GDAL_DRIVER_PATH", nullptr);
+    GDALDriverH hDrv = GDALGetDriverByName("JPEG");
+    EXPECT_EQ(hDrv, nullptr);
+    // May trigger error message `/path/to/autotest/gdrivers/data/jpeg/byte_with_xmp.jpg' not recognized as a supported file format. It could have been recognized by driver JPEG, but plugin gdal_JPEG.so is not available in your installation.
+    CPLPushErrorHandler(CPLQuietErrorHandler);
+    GDALClose(
+        GDALOpen(GDRIVERS_DIR "data/jpeg/byte_with_xmp.jpg", GA_ReadOnly));
+    CPLPopErrorHandler();
+    EXPECT_TRUE(
+        strstr(CPLGetLastErrorMsg(),
+               "It could have been recognized by driver JPEG, but plugin "
+               "gdal_JPEG.so is not available in your installation") !=
+        nullptr);
+#else
+    GTEST_SKIP() << "JPEG driver not built or not built as a plugin";
+#endif
+}
+
+TEST(test_deferredplugin, test_nominal)
+{
+#ifdef JPEG_PLUGIN
+    GDALAllRegister();
+    GDALDriverH hDrv = GDALGetDriverByName("JPEG");
+    ASSERT_NE(hDrv, nullptr);
+    EXPECT_NE(GDALDriver::FromHandle(hDrv)->pfnIdentify, nullptr);
+    EXPECT_STREQ(GDALGetMetadataItem(hDrv, GDAL_DCAP_OPEN, nullptr), "YES");
+    EXPECT_EQ(GDALDriver::FromHandle(hDrv)->pfnOpen, nullptr);
+    GDALDatasetH hDS =
+        GDALOpen(GDRIVERS_DIR "data/jpeg/byte_with_xmp.jpg", GA_ReadOnly);
+    EXPECT_NE(hDS, nullptr);
+    EXPECT_NE(GDALDriver::FromHandle(hDrv)->pfnOpen, nullptr);
+    GDALClose(hDS);
+#else
+    GTEST_SKIP() << "JPEG driver not built or not built as a plugin";
+#endif
+}
+
+}  // namespace