CMake: Reject OpenCV 4.5.1, prepare for 4.5.2+

src/CMakeLists.txt

@@ -393,7 +393,14 @@ if(ENABLE_OPENCV)
   find_package(OpenCV 4)
   if(NOT OpenCV_FOUND)
     set(ENABLE_OPENCV FALSE CACHE BOOL
-      "Build with OpenCV algorithms (requires Boost, Protobuf 3)" FORCE)
+      "Build with OpenCV algorithms (requires Protobuf 3)" FORCE)
+    # If we have version 4.5.1, all hope is lost
+  elseif(OpenCV_VERSION VERSION_EQUAL 4.5.1)
+    message(SEND_ERROR [[Incompatible OpenCV version detected
+OpenCV version 4.5.1 contains header errors which make it unable to be used with OpenShot. OpenCV support wil be disabled. Upgrade to OpenCV 4.5.2+ or downgrade to 4.5.0 or earlier, to enable OpenCV.
+See https://github.com/opencv/opencv/issues/19260]])
+    set(ENABLE_OPENCV FALSE CACHE BOOL
+      "Build with OpenCV algorithms (requires Protobuf 3)" FORCE)
   else()
     add_subdirectory(protobuf_messages)
     # Add OpenCV source files
@@ -409,10 +416,20 @@ if(ENABLE_OPENCV)
       opencv_tracking
       openshot_protobuf
     )
-  set(HAVE_OPENCV TRUE CACHE BOOL "Building with OpenCV effects" FORCE)
-  mark_as_advanced(HAVE_OPENCV)
+    set(HAVE_OPENCV TRUE CACHE BOOL "Building with OpenCV effects" FORCE)
+    mark_as_advanced(HAVE_OPENCV)
+
+    # Keep track of OpenCV version, to embed in our version header
+    set(OPENCV_VERSION_STR "${OpenCV_VERSION}" CACHE STRING "OpenCV version linked with" FORCE)
+    mark_as_advanced(OPENCV_VERSION_STR)
+
+    # We may need to use Tracker as opencv::legacy::Tracker
+    if(OpenCV_VERSION VERSION_GREATER_EQUAL 4.5.2)
+      target_compile_definitions(openshot PUBLIC USE_LEGACY_TRACKER=1)
+    endif()
+
   endif()
-endif()
+endif()  # ENABLE_OPENCV
 add_feature_info("OpenCV algorithms" ENABLE_OPENCV "Use OpenCV algorithms")
 
 ###############  LINK LIBRARY  #################