tde_create_translated_desktop: Prevent FTBFS on generated desktop files

Fix FTBFS when translations are missing and the desktop file passed to
tde_create_translated_desktop() is build-time generated.

See TDE/tde-packaging-gentoo #196 for details.

Signed-off-by: Alexander Golubev <fatzer2@gmail.com>
(cherry picked from commit f0a5bcc760)

modules/TDEMacros.cmake

@@ -1799,14 +1799,18 @@ macro( tde_create_translated_desktop )
     if( EXISTS "${_po_dir}" AND IS_DIRECTORY "${_po_dir}" )
       file( GLOB _translations RELATIVE "${_po_dir}" "${_po_dir}/*.po" )
     endif( )
-    if( _translations )
 
-      # prepare a full name for the target
-      get_filename_component( _target ${_basename} ABSOLUTE )
-      file( RELATIVE_PATH _target "${CMAKE_SOURCE_DIR}" "${_target}" )
-      string( REPLACE "/" "+" _target "${_target}-translated" )
+    # prepare a full name for the target
+    get_filename_component( _target ${_basename} ABSOLUTE )
+    file( RELATIVE_PATH _target "${CMAKE_SOURCE_DIR}" "${_target}" )
+    string( REPLACE "/" "+" _target "${_target}-translated" )
 
-      if( NOT TARGET ${_target} )
+    if( NOT TARGET ${_target} )
+
+      # use absolute path for src
+      get_filename_component( _src ${_src} ABSOLUTE )
+
+      if( _translations )
 
         if( DESKTOP_MERGE_MSGFMT )
 
@@ -1825,7 +1829,6 @@ macro( tde_create_translated_desktop )
           endforeach( )
 
           # merge translations command
-          get_filename_component( _src ${_src} ABSOLUTE )
           add_custom_command(
             OUTPUT ${_basename}${_binsuffix}
             COMMAND ${CMAKE_COMMAND} -E env "LINGUAS=${_linguas}" ${MSGFMT_EXECUTABLE} --desktop --template ${_src} -d ${_po_dir} -o ${_basename}${_binsuffix} ${_keywords_arg}
@@ -1839,7 +1842,6 @@ macro( tde_create_translated_desktop )
           string( REPLACE ";" "|" _keywords_match "(${_keywords_desktop})" )
 
           # merge translations command
-          get_filename_component( _src ${_src} ABSOLUTE )
           add_custom_command(
             OUTPUT ${_basename}${_binsuffix}
             COMMAND ${PERL_EXECUTABLE} -p -e  "'s/^${_keywords_match}[ ]*=[ ]*/_\\1=/'" < ${_src} > ${_basename}.in
@@ -1851,15 +1853,20 @@ macro( tde_create_translated_desktop )
         endif( )
 
         # merge translations target
-        add_custom_target( "${_target}" ALL DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${_basename}${_binsuffix} )
 
-      endif()
+      else( )
 
-    else( )
+        # just copy the original file without translations
+        add_custom_command(
+          OUTPUT ${_basename}${_binsuffix}
+          COMMAND ${CMAKE_COMMAND} -E copy ${_src} ${_basename}${_binsuffix}
+          DEPENDS ${_src}
+          COMMENT "Skiping translation and copying source file to ${_sourcename}"
+        )
+
+      endif( )
 
-      # just write the original file without translations
-      file( READ ${_src} _src_data )
-      file( WRITE ${CMAKE_CURRENT_BINARY_DIR}/${_basename}${_binsuffix} "${_src_data}" )
+      add_custom_target( "${_target}" ALL DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${_basename}${_binsuffix} )
 
     endif( )