TortoiseSVN 1.5 and later can use plugins which implement the IBugtraqProvider interface. The interface provides a few methods which plugins can use to interact with the issue tracker.

HRESULT ValidateParameters (
  // Parent window for any UI that needs to be
  // displayed during validation.
  [in] HWND hParentWnd,

  // The parameter string that needs to be validated.
  [in] BSTR parameters,

  // Is the string valid?
  [out, retval] VARIANT_BOOL *valid
);

This method is called from the settings dialog where the user can add and configure the plugin. The parameters string can be used by a plugin to get additional required information, e.g., the URL to the issue tracker, login information, etc. The plugin should verify the parameters string and show an error dialog if the string is not valid. The hParentWnd parameter should be used for any dialog the plugin shows as the parent window. The plugin must return TRUE if the validation of the parameters string is successful. If the plugin returns FALSE, the settings dialog won't allow the user to add the plugin to a working copy path.

HRESULT GetLinkText (
  // Parent window for any (error) UI that needs to be displayed.
  [in] HWND hParentWnd,

  // The parameter string, just in case you need to talk to your
  // web service (e.g.) to find out what the correct text is.
  [in] BSTR parameters,

  // What text do you want to display?
  // Use the current thread locale.
  [out, retval] BSTR *linkText
);

The plugin can provide a string here which is used in the TortoiseSVN commit dialog for the button which invokes the plugin, e.g., "Choose issue" or "Select ticket". Make sure the string is not too long, otherwise it might not fit into the button. If the method returns an error (e.g., E_NOTIMPL), a default text is used for the button.

HRESULT GetCommitMessage (
  // Parent window for your provider's UI.
  [in] HWND hParentWnd,

  // Parameters for your provider.
  [in] BSTR parameters,
  [in] BSTR commonRoot,
  [in] SAFEARRAY(BSTR) pathList,

  // The text already present in the commit message.
  // Your provider should include this text in the new message,
  // where appropriate.
  [in] BSTR originalMessage,

  // The new text for the commit message.
  // This replaces the original message.
  [out, retval] BSTR *newMessage
);

This is the main method of the plugin. This method is called from the TortoiseSVN commit dialog when the user clicks on the plugin button.

The parameters string is the string the user has to enter in the settings dialog when he configures the plugin. Usually a plugin would use this to find the URL of the issue tracker and/or login information or more.

The commonRoot string contains the parent path of all items selected to bring up the commit dialog. Note that this is not the root path of all items which the user has selected in the commit dialog. For the branch/tag dialog, this is the path which is to be copied.

The pathList parameter contains an array of paths (as strings) which the user has selected for the commit.

The originalMessage parameter contains the text entered in the log message box in the commit dialog. If the user has not yet entered any text, this string will be empty.

The newMessage return string is copied into the log message edit box in the commit dialog, replacing whatever is already there. If a plugin does not modify the originalMessage string, it must return the same string again here, otherwise any text the user has entered will be lost.