fix display bug;workaround windows version issues

.gitignore

@@ -0,0 +1,4 @@
+*.exe
+*.log
+resource.syso
+vergrabber.json

gui.go

@@ -67,7 +67,7 @@ func outputResults(installedSoftwareMappings []installedSoftwareMapping) {
 				RecentVersionReleaseDateColumn.Append(widget.NewLabel(
 					entry.MappedStatus.Released))
 			} else {
-				RecentVersionColumn.Append(widget.NewLabel("not available"))
+				RecentVersionReleaseDateColumn.Append(widget.NewLabel("not available"))
 			}
 		}
 	}

main.go

@@ -29,7 +29,7 @@ import (
 	"github.com/rhysd/go-github-selfupdate/selfupdate"
 )
 
-const version = "0.2.3"
+const version = "0.2.4"
 
 const logpath = "UpdateChecker.log"
 

windows_os.go

@@ -59,9 +59,17 @@ func getWindowsVersion() (windowsVersion WindowsVersion, err error) {
 		return WindowsVersion{0, 0, 0, cb, "", pn}, errors.New("Could not get version information from registry - CurrentMajorVersionNumber")
 	}
 
-	relID, _, err := k.GetStringValue("ReleaseId")
-	if err != nil {
-		return WindowsVersion{maj, 0, 0, cb, "", pn}, errors.New("Could not get version information from registry - ReleaseId")
+	// since 20H2 MS has messed up version numbering - working around this here
+	// DisplayVersion seems to be new. We take this field, if available, otherwise ReleaseID
+	relID := ""
+	relDisplayVersion, _, _ := k.GetStringValue("DisplayVersion")
+	if relDisplayVersion != "" {
+		relID = relDisplayVersion
+	} else {
+		relID, _, err = k.GetStringValue("ReleaseId")
+		if err != nil {
+			return WindowsVersion{maj, 0, 0, cb, "", pn}, errors.New("Could not get version information from registry - ReleaseId")
+		}
 	}
 
 	ubr, _, err := k.GetIntegerValue("UBR")