man: prevent cobra "source" comment

Cobra sets a default Source if none is set;

    header.Source = "Auto generated by spf13/cobra"

Set our own Source for the man pages we generate.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

clidocstool_man.go

@@ -33,15 +33,19 @@ func (c *Client) GenManTree(cmd *cobra.Command) error {
 		return err
 	}
 
-	if epoch := os.Getenv("SOURCE_DATE_EPOCH"); c.manHeader != nil && epoch != "" {
-		unixEpoch, err := strconv.ParseInt(epoch, 10, 64)
-		if err != nil {
-			return fmt.Errorf("invalid SOURCE_DATE_EPOCH: %v", err)
+	if c.manHeader != nil {
+		if epoch := os.Getenv("SOURCE_DATE_EPOCH"); epoch != "" {
+			unixEpoch, err := strconv.ParseInt(epoch, 10, 64)
+			if err != nil {
+				return fmt.Errorf("invalid SOURCE_DATE_EPOCH: %v", err)
+			}
+			now := time.Unix(unixEpoch, 0)
+			c.manHeader.Date = &now
+		}
+		if c.manHeader.Source == "" {
+			c.manHeader.Source = "Generated by github.com/docker/cli-docs-tool"
 		}
-		now := time.Unix(unixEpoch, 0)
-		c.manHeader.Date = &now
 	}
-
 	return c.genManTreeCustom(cmd)
 }