Merge branch 'main' into feature/idle-connection-timeout-pr1

Author: priyankatiwari08

.gitattributes

@@ -1,65 +1,5 @@
-###############################################################################
-# Set default behavior to automatically normalize line endings.
-###############################################################################
+# Normalize line endings
 * text=auto
 
-###############################################################################
-# Set default behavior for command prompt diff.
-#
-# This is need for earlier builds of msysgit that does not have it on by
-# default for csharp files.
-# Note: This is only used by command line
-###############################################################################
-#*.cs     diff=csharp
-
-###############################################################################
-# Set the merge driver for project and solution files
-#
-# Merging from the command prompt will add diff markers to the files if there
-# are conflicts (Merging from VS is not affected by the settings below, in VS
-# the diff markers are never inserted). Diff markers may cause the following 
-# file extensions to fail to load in VS. An alternative would be to treat
-# these files as binary and thus will always conflict and require user
-# intervention with every merge. To do so, just uncomment the entries below
-###############################################################################
-#*.sln       merge=binary
-#*.csproj    merge=binary
-#*.vbproj    merge=binary
-#*.vcxproj   merge=binary
-#*.vcproj    merge=binary
-#*.dbproj    merge=binary
-#*.fsproj    merge=binary
-#*.lsproj    merge=binary
-#*.wixproj   merge=binary
-#*.modelproj merge=binary
-#*.sqlproj   merge=binary
-#*.wwaproj   merge=binary
-
-###############################################################################
-# behavior for image files
-#
-# image files are treated as binary by default.
-###############################################################################
-#*.jpg   binary
-#*.png   binary
-#*.gif   binary
-
-###############################################################################
-# diff behavior for common document formats
-# 
-# Convert binary document formats to text before diffing them. This feature
-# is only available from the command line. Turn it on by uncommenting the 
-# entries below.
-###############################################################################
-#*.doc   diff=astextplain
-#*.DOC   diff=astextplain
-#*.docx  diff=astextplain
-#*.DOCX  diff=astextplain
-#*.dot   diff=astextplain
-#*.DOT   diff=astextplain
-#*.pdf   diff=astextplain
-#*.PDF   diff=astextplain
-#*.rtf   diff=astextplain
-#*.RTF   diff=astextplain
-
-.github/workflows/*.lock.yml linguist-generated=true merge=ours
+# Treat workflow lock files as generated
+.github/workflows/*.lock.yml linguist-generated=true merge=ours

.github/copilot-instructions.md

@@ -34,7 +34,7 @@ This project includes several key products and libraries that facilitate SQL Ser
 ## 🛠️ Key Features
 - **Connectivity to SQL Server**: Provides robust and secure connections to SQL Server databases, using various authentication methods, such as Windows Authentication, SQL Server Authentication, and Entra ID authentication, e.g. `ActiveDirectoryIntegrated`, `ActiveDirectoryPassword`, `ActiveDirectoryServicePrincipal`,`ActiveDirectoryInteractive`, `ActiveDirectoryDefault`, and `ActiveDirectoryManagedIdentity`.
 - **Connection Resiliency**: Implements connection resiliency features to handle transient faults and network issues, ensuring reliable database connectivity.
-- **TLS Encryption**: Supports secure connections using TLS protocols to encrypt data in transit. Supports TLS 1.2 and higher, ensuring secure communication with SQL Server. Supported encryption modes are: 
+- **TLS Encryption**: Supports secure connections using TLS protocols to encrypt data in transit. Supports TLS 1.2 and higher, ensuring secure communication with SQL Server. Supported encryption modes are:
   - **Optional**: Encryption is used if available, but not required.
   - **Mandatory**: Encryption is mandatory for the connection.
   - **Strict**: Enforces strict TLS requirements, ensuring only secure connections are established.
@@ -50,6 +50,7 @@ This project includes several key products and libraries that facilitate SQL Ser
 - **Data Encryption**: Supports data encryption for secure data transmission.
 - **Logging and Diagnostics**: Provides event source tracing diagnostic capabilities for troubleshooting.
 - **Failover Support**: Handles automatic failover scenarios for high availability.
+  - Compatibility switch: `Switch.Microsoft.Data.SqlClient.UseLegacyFailoverAlternationOnLoginSqlErrors` (default `false`) can restore legacy alternation behavior in `LoginWithFailover` for login-phase SQL errors.
 - **Cross-Platform Support**: Compatible with both .NET Framework and .NET Core, allowing applications to run on Windows, Linux, and macOS.
 - **Column Encryption AKV Provider**: Supports Azure Key Vault (AKV) provider for acquiring keys from Azure Key Vault to be used for encryption and decryption.
 
@@ -123,7 +124,7 @@ When a new issue is created, follow these steps:
 - Ensure the PR passes all CI checks before merging.
 
 ### ✅ Closing Issues
-- Add a comment summarizing the fix and referencing the PR 
+- Add a comment summarizing the fix and referencing the PR
 
 ### ⚙️ Automating Workflows
 - Auto-label PRs based on folder paths (e.g., changes in `src/Microsoft.Data.SqlClient/src/` → `Area\SqlClient`, changes in `tests/` → `Area\Testing`) and whether they add new public APIs or introduce a breaking change.

.github/instructions/ado-pipelines.instructions.md

@@ -49,7 +49,7 @@ Key parameters:
 - `runAlwaysEncryptedTests` — include AE test set; default `true`
 - `runLegacySqlTests` — include SQL Server 2016/2017 manual-test legs; default `true`
 - `debug` — enable debug output; default `false`
-- `dotnetVerbosity` — MSBuild verbosity; default `normal`
+- `dotnetVerbosity` — build verbosity; default `normal`
 
 ## Build Stage Order
 

.github/instructions/architecture.instructions.md

@@ -49,7 +49,7 @@ The `netcore/` and `netfx/` directories are legacy artifacts from the old dual-p
 - `netcore/ref/` and `netfx/ref/` — **STILL ACTIVE**. Reference assemblies remain in these directories and define the public API surface for each target framework.
 
 ### OS Targeting with `TargetOs`
-The unified project uses a `TargetOs` MSBuild property to handle OS-specific compilation:
+The unified project uses a `TargetOs` build property to handle OS-specific compilation:
 
 ```xml
 <!-- Automatic OS detection -->

.github/instructions/features.instructions.md

@@ -246,6 +246,7 @@ AppContext switches allow runtime behavior changes without modifying connection
 | `Switch.Microsoft.Data.SqlClient.EnableMultiSubnetFailoverByDefault` | `false` | Sets `MultiSubnetFailover=true` as the default for all connections |
 | `Switch.Microsoft.Data.SqlClient.EnableUserAgent` | varies | Controls sending user agent information to SQL Server |
 | `Switch.Microsoft.Data.SqlClient.IgnoreServerProvidedFailoverPartner` | `false` | Ignores failover partner information sent by the server |
+| `Switch.Microsoft.Data.SqlClient.UseLegacyFailoverAlternationOnLoginSqlErrors` | `false` | Restores legacy `LoginWithFailover` alternation for login-phase SQL errors when parser state is not `Closed` |
 | `Switch.Microsoft.Data.SqlClient.LegacyRowVersionNullBehavior` | `false` | Restores legacy null handling for rowversion columns |
 | `Switch.Microsoft.Data.SqlClient.LegacyVarTimeZeroScaleBehaviour` | `false` | Restores legacy zero-scale behavior for time/datetime2/datetimeoffset |
 | `Switch.Microsoft.Data.SqlClient.MakeReadAsyncBlocking` | `false` | Makes ReadAsync behave synchronously (legacy compat) |