Sync eng/common directory with azure-sdk-tools repository

eng/common/scripts/copy-docs-to-blobstorage.ps1

@@ -11,20 +11,26 @@ param (
 $Language = $Language.ToLower()
 
 # Regex inspired but simplified from https://semver.org/#is-there-a-suggested-regular-expression-regex-to-check-a-semver-string
-$SEMVER_REGEX = "^(?<major>0|[1-9]\d*)\.(?<minor>0|[1-9]\d*)\.(?<patch>0|[1-9]\d*)(?:-?(?<prelabel>[a-zA-Z-]*)(?:\.?(?<prenumber>0|[1-9]\d*)))?$"
+$SEMVER_REGEX = "^(?<major>0|[1-9]\d*)\.(?<minor>0|[1-9]\d*)\.(?<patch>0|[1-9]\d*)(?:-?(?<prelabel>[a-zA-Z-]*)(?:\.?(?<prenumber>0|[1-9]\d*))?)?$"
 
 function ToSemVer($version){
     if ($version -match $SEMVER_REGEX)
     {
-        if($matches['prelabel'] -eq $null) {
+        if(-not $matches['prelabel']) {
             # artifically provide these values for non-prereleases to enable easy sorting of them later than prereleases.
             $prelabel = "zzz"
             $prenumber = 999;
             $isPre = $false;
         }
         else {
             $prelabel = $matches["prelabel"]
-            $prenumber = [int]$matches["prenumber"]
+            $prenumber = 0
+
+            # some older packages don't have a prenumber, should handle this
+            if($matches["prenumber"]){
+                $prenumber = [int]$matches["prenumber"]
+            }
+
             $isPre = $true;
         }