TortoiseGit .gitconfig integrity during interrupted upgrade

Configuration State and Recovery

TortoiseGit does not perform automatic integrity checks or repair routines for the %USERPROFILE%\.gitconfig file upon startup, even following a detected upgrade failure. Because the MSI installer treats the .gitconfig as a plain text file rather than a registered MSI resource, partial writes occurring during a forced reboot or crash are not rolled back by the Windows Installer transaction.

Expected Behavior and Fallbacks

When the .gitconfig file is left malformed (containing truncated values or duplicate sections), the behavior is governed by the underlying Git for Windows parser rather than the TortoiseGit shell extension:

• Parsing Logic: Git parses the configuration lazily. If it encounters a malformed section or syntax error, it typically emits a warning to stderr and ignores the problematic section.
• UI Impact: The TortoiseGit shell extension does not surface an error dialog for configuration corruption. It will silently ignore broken sections and fall back to default settings for those specific keys.
• Version Differences: While TortoiseGit 3.x introduced the creation of a .gitconfig.bak during certain operations, this backup is not automatically restored if a partial write occurs; manual intervention is required to recover from the backup.

Manual Verification and Resolution

To determine if your configuration was corrupted during an interrupted upgrade, use the following steps:

1. Validate Syntax: Open a command prompt and run:

   git config --list

   If the file is malformed, Git will output a syntax error indicating the line number of the corruption.
2. Manual Inspection: Open %USERPROFILE%\.gitconfig in a text editor to check for duplicate section headers (e.g., two [user] blocks) or incomplete lines.
3. Resolution: If corruption is found, you can either manually edit the file to remove duplicates or restore the backup file if present:

   copy %USERPROFILE%\.gitconfig.bak %USERPROFILE%\.gitconfig

Diagnostic Requirement

To refine this recommendation, please specify if the .gitconfig is stored on a local NTFS drive or a network-mapped profile, as file locking behaviors during MSI interruptions vary by file system.