Added --no-overwrite flag in core install

Author: cmaglie

cli/core/install.go

@@ -33,6 +33,7 @@ import (
 
 var (
 	postInstallFlags arguments.PostInstallFlags
+	noOverwrite      bool
 )
 
 func initInstallCommand() *cobra.Command {
@@ -54,6 +55,7 @@ func initInstallCommand() *cobra.Command {
 		},
 	}
 	postInstallFlags.AddToCommand(installCommand)
+	installCommand.Flags().BoolVar(&noOverwrite, "no-overwrite", false, tr("Do not overwrite existing platforms (during upgrade or downgrade)."))
 	return installCommand
 }
 
@@ -74,6 +76,7 @@ func runInstallCommand(cmd *cobra.Command, args []string) {
 			Architecture:    platformRef.Architecture,
 			Version:         platformRef.Version,
 			SkipPostInstall: postInstallFlags.DetectSkipPostInstallValue(),
+			NoOverwrite:     noOverwrite,
 		}
 		_, err := core.PlatformInstall(context.Background(), platformInstallRequest, output.ProgressBar(), output.TaskProgress())
 		if err != nil {

commands/core/install.go

@@ -17,6 +17,7 @@ package core
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/arduino/arduino-cli/arduino"
 	"github.com/arduino/arduino-cli/arduino/cores"
@@ -55,6 +56,14 @@ func PlatformInstall(ctx context.Context, req *rpc.PlatformInstallRequest,
 		return &rpc.PlatformInstallResponse{}, nil
 	}
 
+	if req.GetNoOverwrite() {
+		if installed := pm.GetInstalledPlatformRelease(platformRelease.Platform); installed != nil {
+			return nil, fmt.Errorf("%s: %s",
+				tr("Platform %s already installed", installed),
+				tr("could not overwrite"))
+		}
+	}
+
 	if err := installPlatform(pm, platformRelease, tools, downloadCB, taskCB, req.GetSkipPostInstall()); err != nil {
 		return nil, err
 	}