Update a postgres param if it's reset to a previous state (#3713)

Fixes #3712 (cherry picked from commit bc081db)
npgsql · May 9, 2021 · 9d5c342 · 9d5c342
1 parent 93e74c0
commit 9d5c342
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Showing 2 changed files with 12 additions and 4 deletions.
diff --git a/src/Npgsql/NpgsqlConnector.cs b/src/Npgsql/NpgsqlConnector.cs
@@ -2274,16 +2274,21 @@ void ReadParameterStatus(ReadOnlySpan<byte> incomingName, ReadOnlySpan<byte> inc
             byte[] rawName;
             byte[] rawValue;
 
-            foreach (var current in _rawParameters)
-                if (incomingName.SequenceEqual(current.Name))
+            for (var i = 0; i < _rawParameters.Count; i++)
+            {
+                (var currentName, var currentValue) = _rawParameters[i];
+                if (incomingName.SequenceEqual(currentName))
                 {
-                    if (incomingValue.SequenceEqual(current.Value))
+                    if (incomingValue.SequenceEqual(currentValue))
                         return;
 
-                    rawName = current.Name;
+                    rawName = currentName;
                     rawValue = incomingValue.ToArray();
+                    _rawParameters[i] = (rawName, rawValue);
+
                     goto ProcessParameter;
                 }
+            }
 
             rawName = incomingName.ToArray();
             rawValue = incomingValue.ToArray();

diff --git a/test/Npgsql.Tests/ConnectionTests.cs b/test/Npgsql.Tests/ConnectionTests.cs
@@ -1388,10 +1388,13 @@ public async Task ChangeParameter()
 
             using (var conn = await OpenConnectionAsync())
             {
+            	var defaultApplicationName = conn.PostgresParameters["application_name"];
                 await conn.ExecuteNonQueryAsync("SET application_name = 'some_test_value'");
                 Assert.That(conn.PostgresParameters["application_name"], Is.EqualTo("some_test_value"));
                 await conn.ExecuteNonQueryAsync("SET application_name = 'some_test_value2'");
                 Assert.That(conn.PostgresParameters["application_name"], Is.EqualTo("some_test_value2"));
+                await conn.ExecuteNonQueryAsync($"SET application_name = '{defaultApplicationName}'");
+            	Assert.That(conn.PostgresParameters["application_name"], Is.EqualTo(defaultApplicationName));
             }
         }