CMake: Fixup SpanDSP's TIFF includes.

Add TIFF_INCLUDE_DIR to SPANDSP_INCLUDE_DIRS, but only if TIFF has been
found.

Ping #17477.

CMakeLists.txt

@@ -1249,7 +1249,6 @@ ws_find_package(NL ENABLE_NETLINK HAVE_LIBNL)
 ws_find_package(SBC ENABLE_SBC HAVE_SBC)
 
 # SpanDSP codec
-find_package(TIFF QUIET)
 ws_find_package(SPANDSP ENABLE_SPANDSP HAVE_SPANDSP)
 
 ws_find_package(BCG729 ENABLE_BCG729 HAVE_BCG729)

cmake/modules/FindSPANDSP.cmake

@@ -14,6 +14,9 @@ if( NOT WIN32)
   pkg_search_module(SPANDSP spandsp)
 endif()
 
+# spandsp.h includes tiffio.h.
+find_package(TIFF QUIET)
+
 find_path( SPANDSP_INCLUDE_DIR
   NAMES spandsp.h
   HINTS
@@ -35,6 +38,9 @@ find_package_handle_standard_args( SPANDSP DEFAULT_MSG SPANDSP_LIBRARY SPANDSP_I
 
 if( SPANDSP_FOUND )
   set( SPANDSP_INCLUDE_DIRS ${SPANDSP_INCLUDE_DIR} )
+  if( TIFF_FOUND )
+    list(APPEND SPANDSP_INCLUDE_DIRS ${TIFF_INCLUDE_DIR})
+  endif()
   set( SPANDSP_LIBRARIES ${SPANDSP_LIBRARY} )
   if (WIN32)
     set ( SPANDSP_DLL_DIR "${SPANDSP_HINTS}/bin"

plugins/codecs/G722/CMakeLists.txt

@@ -38,11 +38,7 @@ target_include_directories(g722 PRIVATE ${CMAKE_SOURCE_DIR}/codecs)
 
 target_link_libraries(g722 wsutil ${SPANDSP_LIBRARIES})
 
-target_include_directories(g722
-	SYSTEM PRIVATE
-		${SPANDSP_INCLUDE_DIRS}
-		${TIFF_INCLUDE_DIR}
-	)
+target_include_directories(g722 SYSTEM PRIVATE ${SPANDSP_INCLUDE_DIRS})
 
 install_plugin(g722 codecs)
 

plugins/codecs/G726/CMakeLists.txt

@@ -38,11 +38,7 @@ target_include_directories(g726 PRIVATE ${CMAKE_SOURCE_DIR}/codecs)
 
 target_link_libraries(g726 wsutil ${SPANDSP_LIBRARIES})
 
-target_include_directories(g726
-	SYSTEM PRIVATE
-		${SPANDSP_INCLUDE_DIRS}
-		${TIFF_INCLUDE_DIR}
-	)
+target_include_directories(g726 SYSTEM PRIVATE ${SPANDSP_INCLUDE_DIRS})
 
 install_plugin(g726 codecs)