e272a77964
784b7e2f("gitk: Fix "External diff" with separate work tree", 2011-04-04) added an unconditional call to "git rev-parse --show-toplevel" to set up a global variable quite early in the course of the program, so that the location of the working tree can later be known if/when the user chooses to run the external diff via the external_diff_get_one_file proc. Before that change, the external diff code used to assume that the parent directory of ".git" directory is the top-level of the working tree. Recent versions of git however notices that "rev-parse --show-toplevel" executed in a bare repository is an error, which makes gitk stop, even before the user could attempt to run external diff. Use the gitworktree helper introduced in65bb0bda("gitk: Fix the display of files when filtered by path", 2011-12-13), which is prepared to see failures from "rev-parse --show-toplevel" and other means it tries to find the top-level of the working tree instead to work around this issue. The resulting value in $worktree global, when run in a bare repository, is bogus, but the code is not prepared to run external diff correctly without a working tree anyway ;-) [paulus@ozlabs.org - folded in fix from Eric Sunshine] Helped-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>