Index: src/pager.c
==================================================================
--- src/pager.c
+++ src/pager.c
@@ -4368,11 +4368,12 @@
     z = zUri = &zFilename[sqlite3Strlen30(zFilename)+1];
     while( *z ){
       z += sqlite3Strlen30(z)+1;
       z += sqlite3Strlen30(z)+1;
     }
-    nUri = &z[1] - zUri;
+    nUri = (int)(&z[1] - zUri);
+    assert( nUri>=0 );
     if( rc==SQLITE_OK && nPathname+8>pVfs->mxPathname ){
       /* This branch is taken when the journal path required by
       ** the database being opened will be more than pVfs->mxPathname
       ** bytes in length. This means the database cannot be opened,
       ** as it will not be possible to open the journal file or even