Throw when too many parameter sets are defined (#17881)

src/System.Management.Automation/engine/MergedCommandParameterMetadata.cs

@@ -163,6 +163,13 @@ namespace System.Management.Automation
         /// </summary>
         private uint _nextAvailableParameterSetIndex;
 
+        /// <summary>
+        /// The maximum number of parameter sets allowed. Limit is set by the use
+        /// of a uint bitmask to store which parameter sets a parameter is included in.
+        /// See <see cref="ParameterSetSpecificMetadata.ParameterSetFlag"/>.
+        /// </summary>
+        private const uint MaxParameterSetCount = 32;
+
         /// <summary>
         /// Gets the number of parameter sets that were declared for the command.
         /// </summary>
@@ -228,7 +235,7 @@ namespace System.Management.Automation
                 // A parameter set name should only be added once
                 if (index == -1)
                 {
-                    if (_nextAvailableParameterSetIndex == uint.MaxValue)
+                    if (_nextAvailableParameterSetIndex >= MaxParameterSetCount)
                     {
                         // Don't let the parameter set index overflow
                         ParsingMetadataException parsingException =

test/powershell/Language/Scripting/ParameterBinding.Tests.ps1

@@ -170,6 +170,19 @@ Describe "Tests for parameter binding" -Tags "CI" {
         ( get-foo -b b a c d ) -join ',' | Should -BeExactly 'a,c,d'
     }
 
+    It 'Too many parameter sets defined' {
+        $scriptblock = {
+            param($numSets=1)
+            $parameters = (1..($numSets) | ForEach-Object { "[Parameter(parametersetname='set$_')]`$a$_" }) -join ', '
+            $body = "param($parameters) 'working'"
+            $sb = [scriptblock]::Create($body)
+            & $sb -a1 123
+        }
+
+        & $scriptblock -numSets 32 | Should -Be 'working'
+        { & $scriptblock -numSets 33 } | Should -Throw -ErrorId 'ParsingTooManyParameterSets'
+    }
+
     It 'Default parameter set with value from remaining arguments case 1' {
         function get-foo
         {