Pass global flags down to subcommands (#54)

Fix #51

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://gitea.com/gitea/changelog/pulls/54
Reviewed-by: 6543 <6543@obermui.de>
Reviewed-by: Norwin <noerw@noreply.gitea.io>
Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-committed-by: Andrew Thornton <art27@cantab.net>

.gitignore

@@ -3,4 +3,7 @@
 
 # Binaries
 /changelog
-/changelog.exe
+/changelog.exe
+
+# Go
+/vendor/

README.md

@@ -1,4 +1,5 @@
 # Changelog
+
 A changelog generator for Gitea
 
 [![Build Status](https://drone.gitea.com/api/badges/gitea/changelog/status.svg)](https://drone.gitea.com/gitea/changelog)
@@ -19,18 +20,21 @@ See the [changelog.example.yml](config/changelog.example.yml) example file.
 
 ## Usage
 
-#### Changelog Entries
+### Changelog Entries
-```
+
-changelog -m=1.11.0 -c=/path/to/my_config_file generate
+```sh
+changelog generate -m=1.11.0 -c=/path/to/my_config_file
 ```
 
-#### Contributors List
+### Contributors List
-```
+
-changelog -m=1.11.0 -c=/path/to/my_config_file contributors
+```sh
+changelog contributors -m=1.11.0 -c=/path/to/my_config_file
 ```
 
 ## Building
-```
+
+```sh
 go build
 ```
 

cmd/cmd.go

@@ -80,6 +80,7 @@ func New() *cli.App {
 			Init,
 		},
 	}
+	copyGlobalFlags(app)
 	return app
 }
 
@@ -95,3 +96,28 @@ func getDefaultConfigFile() string {
 	}
 	return ""
 }
+
+func copyGlobalFlags(app *cli.App) {
+	for _, command := range app.Commands {
+		originalFlagNames := make([]string, 0, len(command.Flags))
+		for _, flag := range command.Flags {
+			originalFlagNames = append(originalFlagNames, flag.Names()...)
+		}
+
+		for _, flag := range app.Flags {
+			found := false
+		flagNameLoop:
+			for _, name := range flag.Names() {
+				for _, originalName := range originalFlagNames {
+					if name == originalName {
+						found = true
+						break flagNameLoop
+					}
+				}
+			}
+			if !found {
+				command.Flags = append(command.Flags, flag)
+			}
+		}
+	}
+}