git-gui: Create new branches from a tag.

I'm missing the possibility to base a new branch on a tag.
The following adds a tag drop down to the new branch dialog.

Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/git-gui.sh b/git-gui.sh
index 04afb36343410ca235b2fd5b8b8b4b7b8859d931..9ce5a3bdc3805ed0054ee1c3a7b1cd1d06a9e8c1 100755 (executable)
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -1916,11 +1916,24 @@ proc all_tracking_branches {} {
        return [lsort -unique $all_trackings]
 }
 
+proc load_all_tags {} {
+       set all_tags [list]
+       set fd [open "| git for-each-ref --format=%(refname) refs/tags" r]
+       while {[gets $fd line] > 0} {
+               if {![regsub ^refs/tags/ $line {} name]} continue
+               lappend all_tags $name
+       }
+       close $fd
+
+       return [lsort $all_tags]
+}
+
 proc do_create_branch_action {w} {
        global all_heads null_sha1 repo_config
        global create_branch_checkout create_branch_revtype
        global create_branch_head create_branch_trackinghead
        global create_branch_name create_branch_revexp
+       global create_branch_tag
 
        set newbranch $create_branch_name
        if {$newbranch eq {}
@@ -1959,6 +1972,7 @@ proc do_create_branch_action {w} {
        switch -- $create_branch_revtype {
        head {set rev $create_branch_head}
        tracking {set rev $create_branch_trackinghead}
+       tag {set rev $create_branch_tag}
        expression {set rev $create_branch_revexp}
        }
        if {[catch {set cmt [git rev-parse --verify "${rev}^0"]}]} {
@@ -2004,6 +2018,8 @@ trace add variable create_branch_head write \
        [list radio_selector create_branch_revtype head]
 trace add variable create_branch_trackinghead write \
        [list radio_selector create_branch_revtype tracking]
+trace add variable create_branch_tag write \
+       [list radio_selector create_branch_revtype tag]
 
 trace add variable delete_branch_head write \
        [list radio_selector delete_branch_checktype head]
@@ -2015,6 +2031,7 @@ proc do_create_branch {} {
        global create_branch_checkout create_branch_revtype
        global create_branch_head create_branch_trackinghead
        global create_branch_name create_branch_revexp
+       global create_branch_tag
 
        set w .branch_editor
        toplevel $w
@@ -2078,6 +2095,19 @@ proc do_create_branch {} {
                        $all_trackings
                grid $w.from.tracking_r $w.from.tracking_m -sticky w
        }
+       set all_tags [load_all_tags]
+       if {$all_tags ne {}} {
+               set create_branch_tag [lindex $all_tags 0]
+               radiobutton $w.from.tag_r \
+                       -text {Tag:} \
+                       -value tag \
+                       -variable create_branch_revtype \
+                       -font font_ui
+               eval tk_optionMenu $w.from.tag_m \
+                       create_branch_tag \
+                       $all_tags
+               grid $w.from.tag_r $w.from.tag_m -sticky w
+       }
        radiobutton $w.from.exp_r \
                -text {Revision Expression:} \
                -value expression \