version: return correct Meta.MajorMinorPatch in non-dev builds

Signed-off-by: David Anderson <danderson@tailscale.com>

version-embed.go

@@ -6,8 +6,13 @@ package tailscaleroot
 
 import _ "embed"
 
+// VersionDotTxt is the contents of VERSION.txt. Despite the tempting filename,
+// this does not necessarily contain the accurate version number of the build, which
+// depends on the branch type and how it was built. To get version information, use
+// the version package instead.
+//
 //go:embed VERSION.txt
-var Version string
+var VersionDotTxt string
 
 //go:embed ALPINE.txt
 var AlpineDockerTag string

version/prop.go

@@ -6,7 +6,6 @@ package version
 import (
 	"strings"
 
-	tailscaleroot "tailscale.com"
 	"tailscale.com/tailcfg"
 )
 
@@ -95,7 +94,7 @@ type Meta struct {
 // GetMeta returns version metadata about the current build.
 func GetMeta() Meta {
 	return Meta{
-		MajorMinorPatch: strings.TrimSpace(tailscaleroot.Version),
+		MajorMinorPatch: majorMinorPatch,
 		Short:           Short,
 		Long:            Long,
 		GitCommit:       GitCommit,

version/version.go

@@ -80,6 +80,9 @@ var (
 
 	// isWindowsGUI is whether the current binary is the Windows GUI binary.
 	isWindowsGUI bool
+
+	// majorMinorPatch is the major.minor.patch portion of Short.
+	majorMinorPatch string
 )
 
 func init() {
@@ -89,6 +92,12 @@ func init() {
 }
 
 func initVersion() {
+	defer func() {
+		// Must be run after Short has been initialized, easiest way to do that
+		// is a defer.
+		majorMinorPatch, _, _ = strings.Cut(Short, "-")
+	}()
+
 	if Long != "" && Short != "" {
 		// Built in the recommended way, using build_dist.sh.
 		return
@@ -98,7 +107,7 @@ func initVersion() {
 	// stamping.
 	bi, ok := debug.ReadBuildInfo()
 	if !ok {
-		Long = strings.TrimSpace(tailscaleroot.Version) + "-ERR-BuildInfo"
+		Long = strings.TrimSpace(tailscaleroot.VersionDotTxt) + "-ERR-BuildInfo"
 		Short = Long
 		return
 	}
@@ -126,7 +135,7 @@ func initVersion() {
 	}
 
 	// Backup path, using Go 1.18's built-in git stamping.
-	Short = strings.TrimSpace(tailscaleroot.Version) + "-dev" + commitDate
+	Short = strings.TrimSpace(tailscaleroot.VersionDotTxt) + "-dev" + commitDate
 	Long = Short + "-t" + commitHashAbbrev + dirty
 }