Fix crash in upload if the upload tool platform is missing (#2211)

* Added integration test

* Fixed panic in upload tool selection

Author: cmaglie

Diff for: commands/upload/upload.go

@@ -272,13 +272,18 @@ func runProgramAction(pme *packagemanager.Explorer,
 			Property: fmt.Sprintf("%s.tool.%s", action, port.Protocol), // TODO: Can be done better, maybe inline getToolID(...)
 			Value:    uploadToolID}
 	} else if len(split) == 2 {
+		p := pme.FindPlatform(&packagemanager.PlatformReference{
+			Package:              split[0],
+			PlatformArchitecture: boardPlatform.Platform.Architecture,
+		})
+		if p == nil {
+			return &arduino.PlatformNotFoundError{Platform: split[0] + ":" + boardPlatform.Platform.Architecture}
+		}
 		uploadToolID = split[1]
-		uploadToolPlatform = pme.GetInstalledPlatformRelease(
-			pme.FindPlatform(&packagemanager.PlatformReference{
-				Package:              split[0],
-				PlatformArchitecture: boardPlatform.Platform.Architecture,
-			}),
-		)
+		uploadToolPlatform = pme.GetInstalledPlatformRelease(p)
+		if uploadToolPlatform == nil {
+			return &arduino.PlatformNotFoundError{Platform: split[0] + ":" + boardPlatform.Platform.Architecture}
+		}
 	}
 
 	// Build configuration for upload

Diff for: internal/integrationtest/upload/upload_test.go

@@ -579,3 +579,27 @@ func TestCompileAndUploadToPortWithBoardAutodetect(t *testing.T) {
 		require.NoError(t, err)
 	}
 }
+
+func TestPanicIfUploadToolReferenceAnInexistentPlatform(t *testing.T) {
+	// See: https://github.com/arduino/arduino-cli/issues/2042
+
+	env, cli := integrationtest.CreateArduinoCLIWithEnvironment(t)
+	defer env.CleanUp()
+
+	// Run update-index with our test index
+	_, _, err := cli.Run("core", "install", "arduino:[email protected]")
+	require.NoError(t, err)
+
+	// Install test data into datadir
+	boardsTxt := cli.DataDir().Join("packages", "arduino", "hardware", "avr", "1.8.5", "boards.txt")
+	boardsTxtData, err := boardsTxt.ReadFile()
+	require.NoError(t, err)
+	boardsTxtData = append(boardsTxtData, []byte("uno.upload.tool.default=foo:bar\n")...)
+	require.NoError(t, boardsTxt.WriteFile(boardsTxtData))
+
+	sketch, err := paths.New("..", "testdata", "bare_minimum").Abs()
+	require.NoError(t, err)
+
+	stdout, _, _ := cli.Run("compile", "-b", "arduino:avr:uno", "--upload", sketch.String())
+	require.NotContains(t, stdout, []byte("panic:"))
+}