fix build with python3 only

cmake/OpenCVDetectPython.cmake

@@ -232,8 +232,13 @@ find_python(3.4 "${MIN_VER_PYTHON3}" PYTHON3_LIBRARY PYTHON3_INCLUDE_DIR
     PYTHON3_INCLUDE_DIR PYTHON3_INCLUDE_DIR2 PYTHON3_PACKAGES_PATH
     PYTHON3_NUMPY_INCLUDE_DIRS PYTHON3_NUMPY_VERSION)
 
-# Use Python 2 as default Python interpreter
-if(PYTHON2INTERP_FOUND)
+
+if(PYTHON_DEFAULT_EXECUTABLE)
+    set(PYTHON_DEFAULT_AVAILABLE "TRUE")
+elseif(PYTHON2INTERP_FOUND) # Use Python 2 as default Python interpreter
     set(PYTHON_DEFAULT_AVAILABLE "TRUE")
     set(PYTHON_DEFAULT_EXECUTABLE "${PYTHON2_EXECUTABLE}")
+elseif(PYTHON3INTERP_FOUND) # Use Python 2 as fallback Python interpreter (if there is no Python 2)
+    set(PYTHON_DEFAULT_AVAILABLE "TRUE")
+    set(PYTHON_DEFAULT_EXECUTABLE "${PYTHON3_EXECUTABLE}")
 endif()

modules/java/generator/gen_java.py

@@ -924,6 +924,10 @@ class FuncInfo(GeneralInfo):
     def __repr__(self):
         return Template("FUNC <$ctype $namespace.$classpath.$name $args>").substitute(**self.__dict__)
 
+    def __lt__(self, other):
+        return self.__repr__() < other.__repr__()
+
+
 class JavaWrapperGenerator(object):
     def __init__(self):
         self.clear()