git-gui: Detect full path when parsing arguments
git-gui: Detect full path when parsing arguments

When running "git-gui blame" from a subfolder (which means prefix is
non-empty), if we pass a full path as argument, the argument parsing
will fail to recognize the argument as a file name, because prefix is
prepended to the argument.

This patch handles that scenario by adding an additional branch that
checks the file name without using the prefix.

Signed-off-by: Andrew Wong <284ec9141727d0bb92378cf0a865336c51a1e413@gmail.com>
Signed-off-by: Pat Thoyts <fe43a83262eef1680511f524a1e74d43c633cffe@users.sourceforge.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git