option: Don't apply rmtrailingws in case of timed autosave (#2850)

cmd/micro/micro.go

@@ -418,7 +418,7 @@ func DoEvent() {
 		f.Function(f.Output, f.Args)
 	case <-config.Autosave:
 		for _, b := range buffer.OpenBuffers {
-			b.Save()
+			b.AutoSave()
 		}
 	case <-shell.CloseTerms:
 	case event = <-screen.Events:

internal/buffer/save.go

@@ -93,20 +93,25 @@ func (b *Buffer) Save() error {
 	return b.SaveAs(b.Path)
 }
 
+// AutoSave saves the buffer to its default path
+func (b *Buffer) AutoSave() error {
+	return b.saveToFile(b.Path, false, true)
+}
+
 // SaveAs saves the buffer to a specified path (filename), creating the file if it does not exist
 func (b *Buffer) SaveAs(filename string) error {
-	return b.saveToFile(filename, false)
+	return b.saveToFile(filename, false, false)
 }
 
 func (b *Buffer) SaveWithSudo() error {
 	return b.SaveAsWithSudo(b.Path)
 }
 
 func (b *Buffer) SaveAsWithSudo(filename string) error {
-	return b.saveToFile(filename, true)
+	return b.saveToFile(filename, true, false)
 }
 
-func (b *Buffer) saveToFile(filename string, withSudo bool) error {
+func (b *Buffer) saveToFile(filename string, withSudo bool, autoSave bool) error {
 	var err error
 	if b.Type.Readonly {
 		return errors.New("Cannot save readonly buffer")
@@ -118,7 +123,7 @@ func (b *Buffer) saveToFile(filename string, withSudo bool) error {
 		return errors.New("Save with sudo not supported on Windows")
 	}
 
-	if b.Settings["rmtrailingws"].(bool) {
+	if !autoSave && b.Settings["rmtrailingws"].(bool) {
 		for i, l := range b.lines {
 			leftover := util.CharacterCount(bytes.TrimRightFunc(l.data, unicode.IsSpace))
 

runtime/help/options.md

@@ -315,7 +315,10 @@ Here are the available options:
    default value: `prompt`
 
 * `rmtrailingws`: micro will automatically trim trailing whitespaces at ends of
-   lines. Note: This setting overrides `keepautoindent`
+   lines.
+   Note: This setting overrides `keepautoindent` and isn't used at timed `autosave`
+   or forced `autosave` in case the buffer didn't change. A manual save will
+   involve the action regardless if the buffer has been changed or not.
 
 	default value: `false`