FindTHEORA: avoid duplicate imported targets

CMake/FindTHEORA.cmake

@@ -44,20 +44,26 @@ if (THEORA_FOUND)
   set(THEORA_LIBRARIES "${THEORA_LIBRARY}" "${THEORA_enc_LIBRARY}" "${THEORA_dec_LIBRARY}")
   set(THEORA_INCLUDE_DIRS "${THEORA_INCLUDE_DIR}")
 
-  add_library(THEORA::THEORA UNKNOWN IMPORTED)
-  set_target_properties(THEORA::THEORA PROPERTIES
-    IMPORTED_LOCATION "${THEORA_LIBRARY}"
-    INTERFACE_INCLUDE_DIRECTORIES ${THEORA_INCLUDE_DIR}
-    INTERFACE_LINK_LIBRARIES OGG::OGG)
-
-  add_library(THEORA::ENC UNKNOWN IMPORTED)
-  set_target_properties(THEORA::ENC PROPERTIES
-    IMPORTED_LOCATION "${THEORA_enc_LIBRARY}"
-    INTERFACE_INCLUDE_DIRECTORIES ${THEORA_INCLUDE_DIR}
-    INTERFACE_LINK_LIBRARIES OGG::OGG)
-
-  add_library(THEORA::DEC UNKNOWN IMPORTED)
-  set_target_properties(THEORA::DEC PROPERTIES
-    IMPORTED_LOCATION "${THEORA_dec_LIBRARY}"
-    INTERFACE_INCLUDE_DIRECTORIES ${THEORA_INCLUDE_DIR})
+  if (NOT TARGET THEORA::THEORA)
+    add_library(THEORA::THEORA UNKNOWN IMPORTED)
+    set_target_properties(THEORA::THEORA PROPERTIES
+      IMPORTED_LOCATION "${THEORA_LIBRARY}"
+      INTERFACE_INCLUDE_DIRECTORIES ${THEORA_INCLUDE_DIR}
+      INTERFACE_LINK_LIBRARIES OGG::OGG)
+  endif ()
+
+  if (NOT TARGET THEORA::ENC)
+    add_library(THEORA::ENC UNKNOWN IMPORTED)
+    set_target_properties(THEORA::ENC PROPERTIES
+      IMPORTED_LOCATION "${THEORA_enc_LIBRARY}"
+      INTERFACE_INCLUDE_DIRECTORIES ${THEORA_INCLUDE_DIR}
+      INTERFACE_LINK_LIBRARIES OGG::OGG)
+  endif()
+
+  if (NOT TARGET THEORA::DEC)
+    add_library(THEORA::DEC UNKNOWN IMPORTED)
+    set_target_properties(THEORA::DEC PROPERTIES
+      IMPORTED_LOCATION "${THEORA_dec_LIBRARY}"
+      INTERFACE_INCLUDE_DIRECTORIES ${THEORA_INCLUDE_DIR})
+  endif()
 endif ()