From 8570e006ed74f8ffc047477724430e7b9758ca50 Mon Sep 17 00:00:00 2001
From: Manish Vasani <mavasani@microsoft.com>
Date: Tue, 1 Oct 2019 10:50:40 -0700
Subject: [PATCH] Fix NRE in recently added
 AssigningSymbolAndItsMemberInSameStatement analyzer

Handle null operation type, which is possible for OperationKind.None
Found while dogfooding the latest package
---
 ...igningSymbolAndItsMemberInSameStatement.cs | 28 +++++++------------
 ...gSymbolAndItsMemberInSameStatementTests.cs | 15 ++++++++++
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/src/Microsoft.CodeQuality.Analyzers/Core/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatement.cs b/src/Microsoft.CodeQuality.Analyzers/Core/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatement.cs
index aa73798712..bc790d7d45 100644
--- a/src/Microsoft.CodeQuality.Analyzers/Core/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatement.cs
+++ b/src/Microsoft.CodeQuality.Analyzers/Core/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatement.cs
@@ -50,29 +50,21 @@ private void AnalyzeAssignment(OperationAnalysisContext context)
             }
 
             // This analyzer makes sense only for reference type objects
-            if (operationTarget.Instance?.Type.IsValueType == true)
+            if (operationTarget.Instance?.Type?.IsReferenceType != true)
             {
                 return;
             }
 
-            // Search for object equal to operationTarget.Instance further in assignment chain
-            bool isViolationFound = false;
-            if (operationTarget.Instance is ILocalReferenceOperation localInstance)
+            bool isViolationFound = operationTarget.Instance switch
             {
-                isViolationFound = AnalyzeAssignmentToMember(assignmentOperation, localInstance, (a, b) => a.Local.Equals(b.Local));
-            }
-            else if (operationTarget.Instance is IMemberReferenceOperation memberInstance)
-            {
-                isViolationFound = AnalyzeAssignmentToMember(assignmentOperation, memberInstance, (a, b) => a.Member.Equals(b.Member) && a.Instance?.Syntax.ToString() == b.Instance?.Syntax.ToString());
-            }
-            else if (operationTarget.Instance is IParameterReferenceOperation parameterInstance)
-            {
-                isViolationFound = AnalyzeAssignmentToMember(assignmentOperation, parameterInstance, (a, b) => a.Parameter.Equals(b.Parameter));
-            }
-            else
-            {
-                return;
-            }
+                ILocalReferenceOperation localInstance =>
+                    AnalyzeAssignmentToMember(assignmentOperation, localInstance, (a, b) => a.Local.Equals(b.Local)),
+                IMemberReferenceOperation memberInstance =>
+                    AnalyzeAssignmentToMember(assignmentOperation, memberInstance, (a, b) => a.Member.Equals(b.Member) && a.Instance?.Syntax.ToString() == b.Instance?.Syntax.ToString()),
+                IParameterReferenceOperation parameterInstance =>
+                    AnalyzeAssignmentToMember(assignmentOperation, parameterInstance, (a, b) => a.Parameter.Equals(b.Parameter)),
+                _ => false,
+            };
 
             if (isViolationFound)
             {
diff --git a/src/Microsoft.CodeQuality.Analyzers/UnitTests/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatementTests.cs b/src/Microsoft.CodeQuality.Analyzers/UnitTests/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatementTests.cs
index e9dfdf21a1..b340637b9e 100644
--- a/src/Microsoft.CodeQuality.Analyzers/UnitTests/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatementTests.cs
+++ b/src/Microsoft.CodeQuality.Analyzers/UnitTests/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatementTests.cs
@@ -316,5 +316,20 @@ public void Method()
 }
 ", TestValidationMode.AllowCompileErrors);
         }
+
+        [Fact]
+        public void CSharpAssignmentInCodeWithOperationNone()
+        {
+            VerifyCSharpUnsafeCode(@"
+public struct Test
+{
+    public System.IntPtr PtrField;
+    public unsafe void Method(Test a, Test *b)
+    {
+        b->PtrField = a.PtrField;
+    }
+}
+");
+        }
     }
 }