git-gui: Make initial commits work properly.

diff --git a/git-gui b/git-gui
index 12a46e976c0c3f5f6fb366e1c0742e6e74ad6555..e2e0beae95004f2bdcc09e79a59fd5dd2c84d242 100755 (executable)
--- a/git-gui
+++ b/git-gui
@@ -205,6 +205,7 @@ set index_lock_type none
 set HEAD {}
 set PARENT {}
 set commit_type {}
+set empty_tree {}
 
 proc lock_index {type} {
        global index_lock_type disable_on_lock
@@ -240,6 +241,7 @@ proc repository_state {hdvar ctvar} {
        upvar $hdvar hd $ctvar ct
 
        if {[catch {set hd [exec git rev-parse --verify HEAD]}]} {
+               set hd {}
                set ct initial
        } elseif {[file exists [file join $gitdir MERGE_HEAD]]} {
                set ct merge
@@ -248,6 +250,18 @@ proc repository_state {hdvar ctvar} {
        }
 }
 
+proc PARENT {} {
+       global PARENT empty_tree
+
+       if {$PARENT ne {}} {
+               return $PARENT
+       }
+       if {$empty_tree eq {}} {
+               set empty_tree [exec git mktree << {}]
+       }
+       return $empty_tree
+}
+
 proc rescan {after} {
        global HEAD PARENT commit_type
        global ui_index ui_other ui_status_value ui_comm
@@ -257,7 +271,7 @@ proc rescan {after} {
        if {$rescan_active > 0 || ![lock_index read]} return
 
        repository_state new_HEAD new_type
-       if {$commit_type eq {amend}
+       if {[string match amend* $commit_type]
                && $new_type eq {normal}
                && $new_HEAD eq $HEAD} {
        } else {
@@ -296,10 +310,8 @@ proc rescan {after} {
 }
 
 proc rescan_stage2 {fd after} {
-       global gitdir PARENT commit_type
-       global ui_index ui_other ui_status_value ui_comm
-       global rescan_active
-       global buf_rdi buf_rdf buf_rlo
+       global gitdir ui_status_value
+       global rescan_active buf_rdi buf_rdf buf_rlo
 
        if {$fd ne {}} {
                read $fd
@@ -320,7 +332,7 @@ proc rescan_stage2 {fd after} {
 
        set rescan_active 3
        set ui_status_value {Scanning for modified files ...}
-       set fd_di [open "| git diff-index --cached -z $PARENT" r]
+       set fd_di [open "| git diff-index --cached -z [PARENT]" r]
        set fd_df [open "| git diff-files -z" r]
        set fd_lo [open $ls_others r]
 
@@ -532,7 +544,7 @@ files list, to prevent possible confusion.
 
 proc show_diff {path {w {}} {lno {}}} {
        global file_states file_lists
-       global PARENT diff_3way diff_active repo_config
+       global diff_3way diff_active repo_config
        global ui_diff current_diff ui_status_value
 
        if {$diff_active || ![lock_index read]} return
@@ -591,7 +603,7 @@ proc show_diff {path {w {}} {lno {}}} {
        }
        }
 
-       lappend cmd $PARENT
+       lappend cmd [PARENT]
        lappend cmd --
        lappend cmd $path
 
@@ -671,7 +683,7 @@ proc read_diff {fd} {
 proc load_last_commit {} {
        global HEAD PARENT commit_type ui_comm
 
-       if {$commit_type eq {amend}} return
+       if {[string match amend* $commit_type]} return
        if {$commit_type ne {normal}} {
                error_popup "Can't amend a $commit_type commit."
                return
@@ -695,23 +707,24 @@ proc load_last_commit {} {
                return
        }
 
+       if {$parent_count > 1} {
+               error_popup {Can't amend a merge commit.}
+               return
+       }
+
        if {$parent_count == 0} {
-               set commit_type amend
-               set HEAD {}
+               set commit_type amend-initial
                set PARENT {}
-               rescan {set ui_status_value {Ready.}}
        } elseif {$parent_count == 1} {
                set commit_type amend
                set PARENT $parent
-               $ui_comm delete 0.0 end
-               $ui_comm insert end $msg
-               $ui_comm edit modified false
-               $ui_comm edit reset
-               rescan {set ui_status_value {Ready.}}
-       } else {
-               error_popup {You can't amend a merge commit.}
-               return
        }
+
+       $ui_comm delete 0.0 end
+       $ui_comm insert end $msg
+       $ui_comm edit modified false
+       $ui_comm edit reset
+       rescan {set ui_status_value {Ready.}}
 }
 
 proc commit_tree {} {
@@ -722,7 +735,7 @@ proc commit_tree {} {
        # -- Our in memory state should match the repository.
        #
        repository_state curHEAD cur_type
-       if {$commit_type eq {amend}
+       if {[string match amend* $commit_type]
                && $cur_type eq {normal}
                && $curHEAD eq $HEAD} {
        } elseif {$commit_type ne $cur_type || $HEAD ne $curHEAD} {
@@ -2559,13 +2572,18 @@ label $ui_coml -text {Commit Message:} \
        -anchor w \
        -justify left \
        -font font_ui
-trace add variable commit_type write {uplevel #0 {
-       switch -glob $commit_type \
-       initial {$ui_coml conf -text {Initial Commit Message:}} \
-       amend   {$ui_coml conf -text {Amended Commit Message:}} \
-       merge   {$ui_coml conf -text {Merge Commit Message:}} \
-       *       {$ui_coml conf -text {Commit Message:}}
-}}
+proc trace_commit_type {varname args} {
+       global ui_coml commit_type
+       switch -glob -- $commit_type {
+       initial       {set txt {Initial Commit Message:}}
+       amend         {set txt {Amended Commit Message:}}
+       amend-initial {set txt {Amended Initial Commit Message:}}
+       merge         {set txt {Merge Commit Message:}}
+       *             {set txt {Commit Message:}}
+       }
+       $ui_coml conf -text $txt
+}
+trace add variable commit_type write trace_commit_type
 text $ui_comm -background white -borderwidth 1 \
        -undo true \
        -maxundo 20 \