Correctly finalise app to requested name

Requires a little juggling of .exe extension
Fixes #2395

cmd/fyne/internal/commands/install.go

@@ -146,7 +146,10 @@ func (i *Installer) install() error {
 		case "linux", "openbsd", "freebsd", "netbsd":
 			i.installDir = "/" // the tarball contains the structure starting at usr/local
 		case "windows":
-			dirName := p.name[:len(p.name)-4]
+			dirName := p.name
+			if filepath.Ext(p.name) == ".exe" {
+				dirName = p.name[:len(p.name)-4]
+			}
 			i.installDir = filepath.Join(os.Getenv("ProgramFiles"), dirName)
 			err := runAsAdminWindows("mkdir", "\"\""+i.installDir+"\"\"")
 			if err != nil {

cmd/fyne/internal/commands/install_windows.go

@@ -36,5 +36,12 @@ func linkToStartMenu(path, name string) error {
 
 func postInstall(i *Installer) error {
 	p := i.Packager
-	return linkToStartMenu(filepath.Join(i.installDir, filepath.Base(p.exe)), p.name[:len(p.name)-4])
+	appName := p.name
+	appExe := p.name
+	if filepath.Ext(p.name) == ".exe" {
+		appName = p.name[:len(p.name)-4]
+	} else {
+		appExe = appExe+".exe"
+	}
+	return linkToStartMenu(filepath.Join(i.installDir, appExe), appName)
 }

cmd/fyne/internal/commands/package-windows.go

@@ -106,8 +106,19 @@ func (p *Packager) packageWindows() error {
 		return errors.Wrap(err, "Failed to rebuild after adding metadata")
 	}
 
+	appPath := p.exe
+	appName := filepath.Base(p.exe)
+	if filepath.Base(p.exe) != p.name {
+		appName = p.name
+		if filepath.Ext(p.name) != ".exe" {
+			appName = appName + ".exe"
+		}
+		appPath = filepath.Join(filepath.Dir(p.exe), appName)
+		os.Rename(filepath.Base(p.exe), appName)
+	}
+
 	if p.install {
-		err := runAsAdminWindows("copy", "\"\""+p.exe+"\"\"", "\"\""+filepath.Join(p.dir, p.name)+"\"\"")
+		err := runAsAdminWindows("copy", "\"\""+appPath+"\"\"", "\"\""+filepath.Join(p.dir, appName)+"\"\"")
 		if err != nil {
 			return errors.Wrap(err, "Failed to run as administrator")
 		}