use windowsMatchComparer for OSVersion match order

Windows OS version should match based on the full OSVersion. When
sorting a manifest, the entries should be sorted using the `Less`
function.

Signed-off-by: Michael Weibel <michael@helio.exchange>

Author: mweibel

defaults_windows.go

@@ -38,5 +38,5 @@ func DefaultSpec() specs.Platform {
 
 // Default returns the current platform's default platform specification.
 func Default() MatchComparer {
-	return Only(DefaultSpec())
+	return &windowsMatchComparer{Matcher: NewMatcher(DefaultSpec())}
 }

platform_windows_compat.go

@@ -114,18 +114,6 @@ func getWindowsOSVersion(osVersionPrefix string) windowsOSVersion {
 	}
 }
 
-func winRevision(v string) int {
-	parts := strings.Split(v, ".")
-	if len(parts) < 4 {
-		return 0
-	}
-	r, err := strconv.Atoi(parts[3])
-	if err != nil {
-		return 0
-	}
-	return r
-}
-
 type windowsVersionMatcher struct {
 	windowsOSVersion
 }
@@ -149,8 +137,7 @@ type windowsMatchComparer struct {
 func (c *windowsMatchComparer) Less(p1, p2 specs.Platform) bool {
 	m1, m2 := c.Match(p1), c.Match(p2)
 	if m1 && m2 {
-		r1, r2 := winRevision(p1.OSVersion), winRevision(p2.OSVersion)
-		return r1 > r2
+		return p1.OSVersion > p2.OSVersion
 	}
 	return m1 && !m2
 }

platform_windows_compat_test.go

@@ -17,7 +17,10 @@
 package platforms
 
 import (
+	"sort"
 	"testing"
+
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
 // Test the platform compatibility of the different
@@ -82,3 +85,75 @@ func Test_PlatformCompat(t *testing.T) {
 		}
 	}
 }
+
+func Test_PlatformOrder(t *testing.T) {
+	linuxPlatform := specs.Platform{
+		Architecture: "amd64",
+		OS:           "linux",
+		OSVersion:    "",
+		OSFeatures:   nil,
+		Variant:      "",
+	}
+	ws2022Platform := specs.Platform{
+		Architecture: "amd64",
+		OS:           "windows",
+		OSVersion:    "10.0.20348.3091",
+		OSFeatures:   nil,
+		Variant:      "",
+	}
+	ws2025Platform := specs.Platform{
+		Architecture: "amd64",
+		OS:           "windows",
+		OSVersion:    "10.0.26100.2894",
+		OSFeatures:   nil,
+		Variant:      "",
+	}
+	ws2025Rev3000Platform := specs.Platform{
+		Architecture: "amd64",
+		OS:           "windows",
+		OSVersion:    "10.0.26100.3000",
+		OSFeatures:   nil,
+		Variant:      "",
+	}
+
+	tt := []struct {
+		name         string
+		hostPlatform specs.Platform
+		platforms    []specs.Platform
+		wantPlatform specs.Platform
+	}{
+		{
+			name:         "Windows Server 2022 should select 2022",
+			hostPlatform: ws2022Platform,
+			platforms:    []specs.Platform{linuxPlatform, ws2022Platform, ws2025Platform},
+			wantPlatform: ws2022Platform,
+		},
+		{
+			name:         "Windows Server 2025 should select 2025",
+			hostPlatform: ws2025Platform,
+			platforms:    []specs.Platform{linuxPlatform, ws2022Platform, ws2025Platform},
+			wantPlatform: ws2025Platform,
+		},
+		{
+			name:         "Windows Server 2025 should select 2025 latest rev",
+			hostPlatform: ws2025Platform,
+			platforms:    []specs.Platform{linuxPlatform, ws2022Platform, ws2025Rev3000Platform},
+			wantPlatform: ws2025Rev3000Platform,
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			comparer := &windowsMatchComparer{Matcher: NewMatcher(tc.hostPlatform)}
+
+			sort.SliceStable(tc.platforms, func(i, j int) bool {
+				return comparer.Less(tc.platforms[i], tc.platforms[j])
+			})
+
+			if tc.platforms[0].OS != tc.wantPlatform.OS || tc.platforms[0].OSVersion != tc.wantPlatform.OSVersion {
+				t.Errorf("Platform mismatch, want %q/%q, got %q/%q", tc.wantPlatform.OS, tc.wantPlatform.OSVersion, tc.platforms[0].OS, tc.platforms[0].OSVersion)
+			}
+		})
+	}
+
+}