git-gui: remove HEAD detachment implementation for git < 1.5.3

git-gui provides an implementation to detach HEAD on Git versions prior to 1.5.3. Nobody should be using such an old version anymore. (Moreover, since 0730a5a3a, git-gui requires git v2.36 or later). Keep only the code for modern Git. Signed-off-by: Mark Levedahl <mlevedahl@gmail.com> [j6t: message tweaked] Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Taylor Blau <me@ttaylorr.com>

Mark Levedahl committed May 2, 2025 at 11:39 UTC f9a2e8a38f524c04fc493548303488dc180b25bd
1 file changed +2 -12
lib/checkout_op.tcl
+2 -12
@@ -510,18 +510,8 @@ method _update_repo_state {} {
510 delete_this
511 }
512
513 -git-version proc _detach_HEAD {log new} {
514 - >= 1.5.3 {
515 - git update-ref --no-deref -m $log HEAD $new
516 - }
517 - default {
518 - set p [gitdir HEAD]
519 - file delete $p
520 - set fd [open $p w]
521 - fconfigure $fd -translation lf -encoding utf-8
522 - puts $fd $new
523 - close $fd
524 - }
513 +proc _detach_HEAD {log new} {
514 + git update-ref --no-deref -m $log HEAD $new
515 }
516
517 method _confirm_reset {cur} {