git-gui: Implemented amended commits.

Also fixed a bug related that caused a crash if the file currently
in the diff viewer is no longer modified after the commit.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/git-gui b/git-gui
index 0e9e519636530e4ae522333274e2ca5219880ef0..bb89da43320ed53b819fa9f973c6cdaaf8783128 100755 (executable)
--- a/git-gui
+++ b/git-gui
@@ -21,6 +21,10 @@ set update_index_fd {}
 set disable_on_lock [list]
 set index_lock_type none
 
+set HEAD {}
+set PARENT {}
+set commit_type {}
+
 proc lock_index {type} {
        global index_lock_type disable_on_lock
 
@@ -63,14 +67,23 @@ proc repository_state {hdvar ctvar} {
        }
 }
 
-proc update_status {} {
-       global HEAD commit_type
+proc update_status {{final Ready.}} {
+       global HEAD PARENT commit_type
        global ui_index ui_other ui_status_value ui_comm
        global status_active file_states
 
        if {$status_active || ![lock_index read]} return
 
-       repository_state HEAD commit_type
+       repository_state new_HEAD new_type
+       if {$commit_type == {amend} 
+               && $new_type == {normal}
+               && $new_HEAD == $HEAD} {
+       } else {
+               set HEAD $new_HEAD
+               set PARENT $new_HEAD
+               set commit_type $new_type
+       }
+
        array unset file_states
        foreach w [list $ui_index $ui_other] {
                $w conf -state normal
@@ -91,11 +104,11 @@ proc update_status {} {
        set ui_status_value {Refreshing file status...}
        set fd_rf [open "| git update-index -q --unmerged --refresh" r]
        fconfigure $fd_rf -blocking 0 -translation binary
-       fileevent $fd_rf readable [list read_refresh $fd_rf]
+       fileevent $fd_rf readable [list read_refresh $fd_rf $final]
 }
 
-proc read_refresh {fd} {
-       global gitdir HEAD commit_type
+proc read_refresh {fd final} {
+       global gitdir PARENT commit_type
        global ui_index ui_other ui_status_value ui_comm
        global status_active file_states
 
@@ -112,27 +125,27 @@ proc read_refresh {fd} {
 
        set status_active 3
        set ui_status_value {Scanning for modified files ...}
-       set fd_di [open "| git diff-index --cached -z $HEAD" 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]
 
        fconfigure $fd_di -blocking 0 -translation binary
        fconfigure $fd_df -blocking 0 -translation binary
        fconfigure $fd_lo -blocking 0 -translation binary
-       fileevent $fd_di readable [list read_diff_index $fd_di]
-       fileevent $fd_df readable [list read_diff_files $fd_df]
-       fileevent $fd_lo readable [list read_ls_others $fd_lo]
+       fileevent $fd_di readable [list read_diff_index $fd_di $final]
+       fileevent $fd_df readable [list read_diff_files $fd_df $final]
+       fileevent $fd_lo readable [list read_ls_others $fd_lo $final]
 }
 
 proc load_message {file} {
        global gitdir ui_comm
 
        set f [file join $gitdir $file]
-       if {[file exists $f]} {
+       if {[file isfile $f]} {
                if {[catch {set fd [open $f r]}]} {
                        return 0
                }
-               set content [read $fd]
+               set content [string trim [read $fd]]
                close $fd
                $ui_comm delete 0.0 end
                $ui_comm insert end $content
@@ -141,7 +154,7 @@ proc load_message {file} {
        return 0
 }
 
-proc read_diff_index {fd} {
+proc read_diff_index {fd final} {
        global buf_rdi
 
        append buf_rdi [read $fd]
@@ -152,10 +165,10 @@ proc read_diff_index {fd} {
                        display_file $p [string index $m end]_
                }
        }
-       status_eof $fd buf_rdi
+       status_eof $fd buf_rdi $final
 }
 
-proc read_diff_files {fd} {
+proc read_diff_files {fd final} {
        global buf_rdf
 
        append buf_rdf [read $fd]
@@ -166,10 +179,10 @@ proc read_diff_files {fd} {
                        display_file $p _[string index $m end]
                }
        }
-       status_eof $fd buf_rdf
+       status_eof $fd buf_rdf $final
 }
 
-proc read_ls_others {fd} {
+proc read_ls_others {fd final} {
        global buf_rlo
 
        append buf_rlo [read $fd]
@@ -178,21 +191,25 @@ proc read_ls_others {fd} {
        foreach p [lrange $pck 0 end-1] {
                display_file $p _O
        }
-       status_eof $fd buf_rlo
+       status_eof $fd buf_rlo $final
 }
 
-proc status_eof {fd buf} {
+proc status_eof {fd buf final} {
        global status_active $buf
-       global ui_fname_value ui_status_value
+       global ui_fname_value ui_status_value file_states
 
        if {[eof $fd]} {
                set $buf {}
                close $fd
                if {[incr status_active -1] == 0} {
                        unlock_index
-                       set ui_status_value {Ready.}
-                       if {$ui_fname_value != {}} {
+
+                       set ui_status_value $final
+                       if {$ui_fname_value != {} && [array names file_states \
+                               -exact $ui_fname_value] != {}}  {
                                show_diff $ui_fname_value
+                       } else {
+                               clear_diff
                        }
                }
        }
@@ -213,7 +230,7 @@ proc clear_diff {} {
 }
 
 proc show_diff {path} {
-       global file_states HEAD diff_3way diff_active
+       global file_states PARENT diff_3way diff_active
        global ui_diff ui_fname_value ui_fstatus_value ui_status_value
 
        if {$diff_active || ![lock_index read]} return
@@ -227,12 +244,12 @@ proc show_diff {path} {
        set ui_fstatus_value [mapdesc $m $path]
        set ui_status_value "Loading diff of $path..."
 
-       set cmd [list | git diff-index -p $HEAD -- $path]
+       set cmd [list | git diff-index -p $PARENT -- $path]
        switch $m {
        AM {
        }
        MM {
-               set cmd [list | git diff-index -p -c $HEAD $path]
+               set cmd [list | git diff-index -p -c $PARENT $path]
        }
        _O {
                if {[catch {
@@ -320,6 +337,51 @@ proc read_diff {fd} {
 ##
 ## commit
 
+proc load_last_commit {} {
+       global HEAD PARENT commit_type ui_comm
+
+       if {$commit_type == {amend}} return
+       if {$commit_type != {normal}} {
+               error_popup "Can't amend a $commit_type commit."
+               return
+       }
+
+       set msg {}
+       set parent {}
+       set parent_count 0
+       if {[catch {
+                       set fd [open "| git cat-file commit $HEAD" r]
+                       while {[gets $fd line] > 0} {
+                               if {[string match {parent *} $line]} {
+                                       set parent [string range $line 7 end]
+                                       incr parent_count
+                               }
+                       }
+                       set msg [string trim [read $fd]]
+                       close $fd
+               } err]} {
+               error_popup "Error loading commit data for amend:\n$err"
+               return
+       }
+
+       if {$parent_count == 0} {
+               set commit_type amend
+               set HEAD {}
+               set PARENT {}
+               update_status
+       } elseif {$parent_count == 1} {
+               set commit_type amend
+               set PARENT $parent
+               $ui_comm delete 0.0 end
+               $ui_comm insert end $msg
+               $ui_comm edit modified false
+               update_status
+       } else {
+               error_popup {You can't amend a merge commit.}
+               return
+       }
+}
+
 proc commit_tree {} {
        global tcl_platform HEAD gitdir commit_type file_states
        global commit_active ui_status_value
@@ -330,7 +392,10 @@ proc commit_tree {} {
        # -- Our in memory state should match the repository.
        #
        repository_state curHEAD cur_type
-       if {$commit_type != $cur_type || $HEAD != $curHEAD} {
+       if {$commit_type == {amend} 
+               && $cur_type == {normal}
+               && $curHEAD == $HEAD} {
+       } elseif {$commit_type != $cur_type || $HEAD != $curHEAD} {
                error_popup {Last scanned state does not match repository state.
 
 Its highly likely that another Git program modified the
@@ -397,7 +462,7 @@ A good commit message has the following format:
        # -- Ask the pre-commit hook for the go-ahead.
        #
        set pchook [file join $gitdir hooks pre-commit]
-       if {$tcl_platform(platform) == {windows} && [file exists $pchook]} {
+       if {$tcl_platform(platform) == {windows} && [file isfile $pchook]} {
                set pchook [list sh -c \
                        "if test -x \"$pchook\"; then exec \"$pchook\"; fi"]
        } elseif {[file executable $pchook]} {
@@ -422,8 +487,8 @@ A good commit message has the following format:
 }
 
 proc commit_stage2 {fd_wt curHEAD msg} {
-       global single_commit gitdir HEAD commit_type
-       global commit_active ui_status_value comm_ui
+       global single_commit gitdir PARENT commit_type
+       global commit_active ui_status_value ui_comm
 
        gets $fd_wt tree_id
        close $fd_wt
@@ -439,8 +504,8 @@ proc commit_stage2 {fd_wt curHEAD msg} {
        # -- Create the commit.
        #
        set cmd [list git commit-tree $tree_id]
-       if {$commit_type != {initial}} {
-               lappend cmd -p $HEAD
+       if {$PARENT != {}} {
+               lappend cmd -p $PARENT
        }
        if {$commit_type == {merge}} {
                if {[catch {
@@ -457,7 +522,7 @@ proc commit_stage2 {fd_wt curHEAD msg} {
                        return
                }
        }
-       if {$commit_type == {initial}} {
+       if {$PARENT == {}} {
                # git commit-tree writes to stderr during initial commit.
                lappend cmd 2>/dev/null
        }
@@ -482,9 +547,7 @@ proc commit_stage2 {fd_wt curHEAD msg} {
        } else {
                append reflogm {: } $msg
        }
-       set cmd [list git update-ref \
-               -m $reflogm \
-               HEAD $cmt_id $curHEAD]
+       set cmd [list git update-ref -m $reflogm HEAD $cmt_id $curHEAD]
        if {[catch {eval exec $cmd} err]} {
                error_popup "update-ref failed:\n$err"
                set commit_active 0
@@ -506,15 +569,15 @@ proc commit_stage2 {fd_wt curHEAD msg} {
                catch {exec git rerere}
        }
 
-       $comm_ui delete 0.0 end
-       $comm_ui edit modified false
+       $ui_comm delete 0.0 end
+       $ui_comm edit modified false
 
        if {$single_commit} do_quit
 
+       set commit_type {}
        set commit_active 0
-       set ui_status_value "Changes committed as $cmt_id."
        unlock_index
-       update_status
+       update_status "Changes committed as $cmt_id."
 }
 
 ######################################################################
@@ -877,7 +940,7 @@ proc do_gitk {} {
        global tcl_platform ui_status_value starting_gitk_msg
 
        set ui_status_value $starting_gitk_msg
-       after 5000 {
+       after 10000 {
                if {$ui_status_value == $starting_gitk_msg} {
                        set ui_status_value {Ready.}
                }
@@ -953,6 +1016,10 @@ proc do_signoff {} {
        }
 }
 
+proc do_amend_last {} {
+       load_last_commit
+}
+
 proc do_commit {} {
        commit_tree
 }
@@ -1027,6 +1094,11 @@ menu .mbar.commit
        -font $mainfont
 lappend disable_on_lock \
        [list .mbar.commit entryconf [.mbar.commit index last] -state]
+.mbar.commit add command -label {Amend Last Commit} \
+       -command do_amend_last \
+       -font $mainfont
+lappend disable_on_lock \
+       [list .mbar.commit entryconf [.mbar.commit index last] -state]
 .mbar.commit add command -label {Check-in All Files} \
        -command do_checkin_all \
        -accelerator $M1T-U \
@@ -1145,7 +1217,7 @@ $ui_diff tag conf dni -foreground "#a000a0"
 $ui_diff tag conf bold -font [concat $difffont bold]
 
 # -- Commit Area
-frame .vpane.commarea -height 150
+frame .vpane.commarea -height 170
 .vpane add .vpane.commarea -stick nsew
 
 # -- Commit Area Buttons
@@ -1163,6 +1235,12 @@ button .vpane.commarea.buttons.rescan -text {Rescan} \
 pack .vpane.commarea.buttons.rescan -side top -fill x
 lappend disable_on_lock {.vpane.commarea.buttons.rescan conf -state}
 
+button .vpane.commarea.buttons.amend -text {Amend Last} \
+       -command do_amend_last \
+       -font $mainfont
+pack .vpane.commarea.buttons.amend -side top -fill x
+lappend disable_on_lock {.vpane.commarea.buttons.amend conf -state}
+
 button .vpane.commarea.buttons.ciall -text {Check-in All} \
        -command do_checkin_all \
        -font $mainfont