more robust: avoid broken tar.gz;

--- a/lib/Tools/components	Fri Nov 30 15:02:31 2018 +0100
+++ b/lib/Tools/components	Fri Nov 30 16:09:45 2018 +0100
@@ -127,11 +127,13 @@
         type -p curl > /dev/null || fail "Cannot download files: missing curl"
         echo "Getting \"$REMOTE\""
         mkdir -p "$(dirname "$FULL_NAME")"
-        curl --fail --silent "$REMOTE" > "${FULL_NAME}.tar.gz" || \
+        curl --fail --silent "$REMOTE" > "${FULL_NAME}.tar.gz.part" || \
           fail "Failed to download \"$REMOTE\""
-        if perl -e "exit((stat('${FULL_NAME}.tar.gz'))[7] == 0 ? 0 : 1);"
+        if perl -e "exit((stat('${FULL_NAME}.tar.gz.part'))[7] == 0 ? 0 : 1);"
         then
-          rm -f "${FULL_NAME}.tar.gz"
+          rm -f "${FULL_NAME}.tar.gz.part"
+        else
+          mv "${FULL_NAME}.tar.gz.part" "${FULL_NAME}.tar.gz"
         fi
       fi
       if [ -e "${FULL_NAME}.tar.gz" ]; then