design.perl6.org rebuild: avoid clobbering .html files on failure

Author: moritz

util/update-design.perl6.org.sh

@@ -45,7 +45,9 @@ grep -vE '^(#.*|\s*)$' pod6-files | while read LINE
 do
     INPUT=$(echo $LINE | cut -d ' ' -f 1)
     OUTPUT=$(echo $LINE | cut -d ' ' -f 2)
-    perl6-m --doc=HTML "$INPUT" > "$DEST_DIR/$OUTPUT"
+    TEMPFILE=$(tempfile)
+    perl6-m --doc=HTML "$INPUT" > "$TEMPFILE" && mv "$TEMPFILE" "$DEST_DIR/$OUTPUT" \
+        || rm -f "$TEMPFILE"
 done
 
 if [ -z "$NOSSH" ]