Make scala-cli.sh more reliable

The .gz file we download might already be in cache (downloaded manually
by users say), while the uncompressed launcher can be missing.

These changes make sure we uncompress the .gz file if needed, even if it
was already in cache.

Author: alexarchambault

scala-cli.sh

@@ -29,8 +29,14 @@ if [ ! -f "$CACHE_DEST" ]; then
   echo "Downloading $SCALA_CLI_URL"
   curl -fLo "$TMP_DEST" "$SCALA_CLI_URL"
   mv "$TMP_DEST" "$CACHE_DEST"
+fi
+
+if [ ! -f "$SCALA_CLI_BIN_PATH" ]; then
   gunzip -k "$CACHE_DEST"
+fi
+
+if [ ! -x "$SCALA_CLI_BIN_PATH" ]; then
   chmod +x "$SCALA_CLI_BIN_PATH"
 fi
 
-exec "$SCALA_CLI_BIN_PATH" "$@"
+exec "$SCALA_CLI_BIN_PATH" "$@"