branches/zip: page_zip_rec_needs_ext(): Fix a bug that was introduced

in the fix of Mantis issue #73.  With key_block_size=16, we will also
have to check the available space on the uncompressed page.
Otherwise, the clustered index record can be almost 16 kilobytes in
size, and the undo log record will not fit.

include/page0zip.ic

@@ -168,9 +168,11 @@ page_zip_rec_needs_ext(
 		the dense page directory for every record.  But there
 		is no record header.  There should be enough room for
 		one record on an empty leaf page.  Subtract 1 byte for
-		the encoded heap number. */
+		the encoded heap number.  Check also the available space
+		on the uncompressed page. */
 		return(rec_size - (REC_N_NEW_EXTRA_BYTES - 2)
-		       >= (page_zip_empty_size(n_fields, zip_size) - 1));
+		       >= (page_zip_empty_size(n_fields, zip_size) - 1)
+		       || rec_size >= page_get_free_space_of_empty(TRUE) / 2);
 	}
 
 	return(rec_size >= page_get_free_space_of_empty(comp) / 2);