Improve berkeley db detection with CMake

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>

config.h.cmake

@@ -2,3 +2,6 @@
 
 // tdecachegrind
 #cmakedefine HAVE_MMAP 1
+
+// kbabeldict/modules/dbsearchengine
+#cmakedefine USE_DB_H_PATH <@USE_DB_H_PATH@>

kbabel/kbabeldict/modules/dbsearchengine/CMakeLists.txt

@@ -37,6 +37,6 @@ tde_add_kpart( kbabeldict_dbsearchengine AUTOMOC
   SOURCES
     KDBSearchEngine.cpp preferenceswidget.cpp dbse_factory.cpp
     dbseprefwidget.ui database.cpp dbscan.cpp
-  LINK kbabelcommon-shared kbabeldictplugin-shared db
+  LINK kbabelcommon-shared kbabeldictplugin-shared ${BDB_LIBRARY}
   DESTINATION ${PLUGIN_INSTALL_DIR}
 )

kbabel/kbabeldict/modules/dbsearchengine/ConfigureChecks.cmake

@@ -9,13 +9,18 @@
 #
 #################################################
 
+find_file( USE_DB_H_PATH NAMES "db5/db.h" "db4/db.h" "db.h" )
+
 check_c_source_compiles("
-    #include <db.h>
-    void main() { DB *db; db->open(db, 0, 0, NULL, DB_BTREE, DB_CREATE, 0644); } "
+    #include <${USE_DB_H_PATH}>
+    #include <stddef.h>
+    int main() { DB *db; db->open(db, 0, 0, NULL, DB_BTREE, DB_CREATE, 0644); } "
   HAVE_BERKELEY_DB )
 
 if( HAVE_BERKELEY_DB )
-  set( BDB_LIBRARY db )
-else( )
+  find_library( BDB_LIBRARY db PATH_SUFFIXES db5 db4 )
+endif( )
+
+if( NOT BDB_LIBRARY )
   tde_message_fatal( "berkeley db is required, but was not found on your system" )
 endif( )