fix #103: incorrect output path when input is a single file

cmd/um/main.go

@@ -121,13 +121,16 @@ func appMain(c *cli.Context) (err error) {
 		return err
 	}
 
-	if output == "" {
+	var inputDir string
-		// Default to where the input is
 	if inputStat.IsDir() {
-			output = input
+		inputDir = input
 	} else {
-			output = path.Dir(input)
+		inputDir = path.Dir(input)
 	}
+
+	if output == "" {
+		// Default to where the input dir is
+		output = inputDir
 	}
 
 	outputStat, err := os.Stat(output)
@@ -152,7 +155,7 @@ func appMain(c *cli.Context) (err error) {
 	}
 
 	proc := &processor{
-		inputDir:        input,
+		inputDir:        inputDir,
 		outputDir:       output,
 		skipNoopDecoder: c.Bool("skip-noop"),
 		removeSource:    c.Bool("remove-source"),