Fix platform tool dependency determination

The platform tool dependency check was giving false negatives due to comparing pointers instead of version values.

This caused tools to be removed during platform uninstallation even when another installed platform had a dependency on
that tool.

Author: per1234

arduino/cores/cores.go

@@ -218,7 +218,7 @@ func (release *PlatformRelease) RequiresToolRelease(toolRelease *ToolRelease) bo
 	for _, toolDep := range release.Dependencies {
 		if toolDep.ToolName == toolRelease.Tool.Name &&
 			toolDep.ToolPackager == toolRelease.Tool.Package.Name &&
-			toolDep.ToolVersion == toolRelease.Version {
+			toolDep.ToolVersion.Equal(toolRelease.Version) {
 			return true
 		}
 	}

arduino/cores/cores_test.go

@@ -0,0 +1,57 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2020 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to [email protected].
+
+package cores
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	semver "go.bug.st/relaxed-semver"
+)
+
+func TestRequiresToolRelease(t *testing.T) {
+	toolDependencyName := "avr-gcc"
+	toolDependencyVersion := "7.3.0-atmel3.6.1-arduino7"
+	toolDependencyPackager := "arduino"
+
+	release := PlatformRelease{
+		Dependencies: ToolDependencies{
+			{
+				ToolName:     toolDependencyName,
+				ToolVersion:  semver.ParseRelaxed(toolDependencyVersion),
+				ToolPackager: toolDependencyPackager,
+			},
+		},
+	}
+
+	toolRelease := &ToolRelease{
+		Version: semver.ParseRelaxed(toolDependencyVersion + "not"),
+		Tool: &Tool{
+			Name: toolDependencyName + "not",
+			Package: &Package{
+				Name: toolDependencyPackager + "not",
+			},
+		},
+	}
+
+	require.False(t, release.RequiresToolRelease(toolRelease))
+	toolRelease.Tool.Name = toolDependencyName
+	require.False(t, release.RequiresToolRelease(toolRelease))
+	toolRelease.Tool.Package.Name = toolDependencyPackager
+	require.False(t, release.RequiresToolRelease(toolRelease))
+	toolRelease.Version = semver.ParseRelaxed(toolDependencyVersion)
+	require.True(t, release.RequiresToolRelease(toolRelease))
+}