[release/10.0] Fix parameter deduplication logic bug

src/EFCore.Relational/Query/Internal/RelationalParameterProcessor.cs

@@ -38,6 +38,9 @@ private readonly IDictionary<FromSqlExpression, Expression> _visitedFromSqlExpre
     private ParametersCacheDecorator _parametersDecorator;
     private ParameterNameGenerator _parameterNameGenerator;
 
+    private static readonly bool UseOldBehavior37189 =
+        AppContext.TryGetSwitch("Microsoft.EntityFrameworkCore.Issue37189", out var enabled37189) && enabled37189;
+
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
     ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
@@ -117,7 +120,7 @@ private SqlParameterExpression VisitSqlParameter(SqlParameterExpression paramete
             && (existingTypeMapping.Converter is null && typeMapping.Converter is null
                 || existingTypeMapping.Converter is not null && existingTypeMapping.Converter.Equals(typeMapping.Converter)))
         {
-            return parameter;
+            return UseOldBehavior37189 ? parameter : existingParameter;
         }
 
         var uniquifiedName = UniquifyParameterName(parameter.Name);

src/EFCore.Relational/Query/SqlExpressions/JsonScalarExpression.cs

@@ -89,7 +89,7 @@ protected override Expression VisitChildren(ExpressionVisitor visitor)
                     if (newPath is null)
                     {
                         newPath = new PathSegment[Path.Count];
-                        for (var j = 0; j < i; i++)
+                        for (var j = 0; j < i; j++)
                         {
                             newPath[j] = Path[j];
                         }

test/EFCore.SqlServer.FunctionalTests/Query/GearsOfWarQuerySqlServerTest.cs

@@ -8457,7 +8457,7 @@ public override async Task Parameter_used_multiple_times_take_appropriate_inferr
 
 SELECT [c].[Name], [c].[Location], [c].[Nation]
 FROM [Cities] AS [c]
-WHERE [c].[Nation] = @place OR [c].[Location] = @place0 OR [c].[Location] = @place
+WHERE [c].[Nation] = @place OR [c].[Location] = @place0 OR [c].[Location] = @place0
 """);
     }
 

test/EFCore.SqlServer.FunctionalTests/Query/TPCGearsOfWarQuerySqlServerTest.cs

@@ -10889,7 +10889,7 @@ public override async Task Parameter_used_multiple_times_take_appropriate_inferr
 
 SELECT [c].[Name], [c].[Location], [c].[Nation]
 FROM [Cities] AS [c]
-WHERE [c].[Nation] = @place OR [c].[Location] = @place0 OR [c].[Location] = @place
+WHERE [c].[Nation] = @place OR [c].[Location] = @place0 OR [c].[Location] = @place0
 """);
     }
 

test/EFCore.SqlServer.FunctionalTests/Query/TPTGearsOfWarQuerySqlServerTest.cs

@@ -9201,7 +9201,7 @@ public override async Task Parameter_used_multiple_times_take_appropriate_inferr
 
 SELECT [c].[Name], [c].[Location], [c].[Nation]
 FROM [Cities] AS [c]
-WHERE [c].[Nation] = @place OR [c].[Location] = @place0 OR [c].[Location] = @place
+WHERE [c].[Nation] = @place OR [c].[Location] = @place0 OR [c].[Location] = @place0
 """);
     }
 

test/EFCore.SqlServer.FunctionalTests/Query/TemporalGearsOfWarQuerySqlServerTest.cs

@@ -2918,7 +2918,7 @@ public override async Task Parameter_used_multiple_times_take_appropriate_inferr
 
 SELECT [c].[Name], [c].[Location], [c].[Nation], [c].[PeriodEnd], [c].[PeriodStart]
 FROM [Cities] FOR SYSTEM_TIME AS OF '2010-01-01T00:00:00.0000000' AS [c]
-WHERE [c].[Nation] = @place OR [c].[Location] = @place0 OR [c].[Location] = @place
+WHERE [c].[Nation] = @place OR [c].[Location] = @place0 OR [c].[Location] = @place0
 """);
     }