Fix pure expressions setting $? in pipeline chains (#10836)

src/System.Management.Automation/engine/parser/Compiler.cs

@@ -3200,7 +3200,7 @@ namespace System.Management.Automation.Language
                     ExpressionCache.Constant(0)));
             tryBodyExprs.Add(Expression.Label(label0));
             tryBodyExprs.Add(Expression.Assign(dispatchIndex, ExpressionCache.Constant(1)));
-            tryBodyExprs.Add(Compile(currentChain.LhsPipelineChain));
+            tryBodyExprs.Add(CompilePipelineChainElement((PipelineAst)currentChain.LhsPipelineChain));
 
             // Remainder of try statement body
             // L1: dispatchIndex = 2; if ($?) pipeline2;
@@ -3234,7 +3234,7 @@ namespace System.Management.Automation.Language
                     ? s_getDollarQuestion
                     : s_notDollarQuestion;
 
-                tryBodyExprs.Add(Expression.IfThen(dollarQuestionCheck, Compile(currentChain.RhsPipeline)));
+                tryBodyExprs.Add(Expression.IfThen(dollarQuestionCheck, CompilePipelineChainElement(currentChain.RhsPipeline)));
 
                 currentChain = currentChain.Parent as PipelineChainAst;
             }
@@ -3277,6 +3277,24 @@ namespace System.Management.Automation.Language
             return fullyExpandedBlock;
         }
 
+        /// <summary>
+        /// Compile a pipeline as an element in a pipeline chain.
+        /// Needed since pure expressions won't set $? after them.
+        /// <seealso cref="CompileTrappableExpression"/> which does something similar.
+        /// </summary>
+        /// <param name="pipelineAst">The pipeline in the pipeline chain to compile to an expression.</param>
+        /// <returns>The compiled expression to execute the pipeline.</returns>
+        private Expression CompilePipelineChainElement(PipelineAst pipelineAst)
+        {
+            if (pipelineAst.PipelineElements.Count == 1 && pipelineAst.PipelineElements[0] is CommandExpressionAst)
+            {
+                // A single expression - must set $? after the expression.
+                return Expression.Block(Compile(pipelineAst), s_setDollarQuestionToTrue);
+            }
+
+            return Compile(pipelineAst);
+        }
+
         public object VisitPipeline(PipelineAst pipelineAst)
         {
             var temps = new List<ParameterExpression>();

src/System.Management.Automation/engine/parser/token.cs

@@ -790,8 +790,8 @@ namespace System.Management.Automation.Language
 
             #region Flags for operators
 
-            /*               AndAnd */ TokenFlags.BinaryOperator | TokenFlags.ParseModeInvariant,
-            /*                 OrOr */ TokenFlags.BinaryOperator | TokenFlags.ParseModeInvariant,
+            /*               AndAnd */ TokenFlags.ParseModeInvariant,
+            /*                 OrOr */ TokenFlags.ParseModeInvariant,
             /*            Ampersand */ TokenFlags.SpecialOperator | TokenFlags.ParseModeInvariant,
             /*                 Pipe */ TokenFlags.SpecialOperator | TokenFlags.ParseModeInvariant,
             /*                Comma */ TokenFlags.UnaryOperator | TokenFlags.ParseModeInvariant,

test/powershell/Language/Operators/PipelineChainOperator.Tests.ps1

@@ -76,6 +76,8 @@ Describe "Experimental Feature: && and || operators - Feature-Enabled" -Tag CI {
             @{ Statement = '"hi" && testexe -returncode 1'; Output = @('hi', '1') }
             @{ Statement = 'testexe -returncode 1 && "Hi"'; Output = @('1') }
             @{ Statement = 'testexe -returncode 1 || "hi"'; Output = @('1', 'hi') }
+            @{ Statement = '"hello" && get-item macarena_doesnotexist || "there"; "hello" || "there"'; Output = @('hello', 'there', 'hello') }
+            @{ Statement = '1 + 1 && "Hi"'; Output = @(2, 'Hi') }
 
             # Pipeline and native command
             @{ Statement = '1,2,3 | % { $_ + 1 } && testexe -returncode 0'; Output = @('2','3','4','0') }