git-gui: Reenable staging unmerged files by clicking the icon.

This restores functionality of the file icon for unmerged files.
Safety is enforced by loading the diff and checking for lines
that look like conflict markers. If such lines are found, or
the conflict involves deletion and/or symlinks, a confirmation
dialog is presented. Otherwise, the icon immediately stages the
working copy version of the file.

Includes a revert of 2fe5b2ee42897a3acc78e5ddaace3775eb2713ca
(Restore ability to Stage Working Copy for conflicts)

Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com>
Tested-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

3 files changed, 70 insertions, 33 deletions

diff --git a/git-gui.sh b/git-gui.sh
index 03c450d73f..4085e8fea5 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -1059,6 +1059,7 @@ set current_branch {}
 set is_detached 0
 set current_diff_path {}
 set is_3way_diff 0
+set is_conflict_diff 0
 set selected_commit_type new
 
 set nullid "0000000000000000000000000000000000000000"
@@ -2078,19 +2079,21 @@ proc toggle_or_diff {w x y} {
 	$ui_index tag remove in_sel 0.0 end
 	$ui_workdir tag remove in_sel 0.0 end
 
-	# Do not stage files with conflicts
+	# Determine the state of the file
 	if {[info exists file_states($path)]} {
 		set state [lindex $file_states($path) 0]
 	} else {
 		set state {__}
 	}
 
-	if {[string first {U} $state] >= 0} {
-		set col 1
-	}
-
 	# Restage the file, or simply show the diff
 	if {$col == 0 && $y > 1} {
+		# Conflicts need special handling
+		if {[string first {U} $state] >= 0} {
+			merge_stage_workdir $path $w $lno
+			return
+		}
+
 		if {[string index $state 1] eq {O}} {
 			set mmask {}
 		} else {
@@ -3057,11 +3060,6 @@ $ctxmmg add command \
 	-command {merge_resolve_one 1}
 lappend diff_actions [list $ctxmmg entryconf [$ctxmmg index last] -state]
 $ctxmmg add separator
-$ctxmmg add command \
-	-label [mc "Stage Working Copy"] \
-	-command {merge_resolve_one 0}
-lappend diff_actions [list $ctxmmg entryconf [$ctxmmg index last] -state]
-$ctxmmg add separator
 create_common_diff_popup $ctxmmg
 
 proc popup_diff_menu {ctxm ctxmmg x y X Y} {
diff --git a/lib/diff.tcl b/lib/diff.tcl
index b61629676f..abe502d971 100644
--- a/lib/diff.tcl
+++ b/lib/diff.tcl
@@ -69,9 +69,9 @@ A rescan will be automatically started to find other files which may have the sa
 	rescan ui_ready 0
 }
 
-proc show_diff {path w {lno {}} {scroll_pos {}}} {
+proc show_diff {path w {lno {}} {scroll_pos {}} {callback {}}} {
 	global file_states file_lists
-	global is_3way_diff diff_active repo_config
+	global is_3way_diff is_conflict_diff diff_active repo_config
 	global ui_diff ui_index ui_workdir
 	global current_diff_path current_diff_side current_diff_header
 	global current_diff_queue
@@ -92,36 +92,42 @@ proc show_diff {path w {lno {}} {scroll_pos {}}} {
 
 	set s $file_states($path)
 	set m [lindex $s 0]
+	set is_conflict_diff 0
 	set current_diff_path $path
 	set current_diff_side $w
 	set current_diff_queue {}
 	ui_status [mc "Loading diff of %s..." [escape_path $path]]
 
+	set cont_info [list $scroll_pos $callback]
+
 	if {[string first {U} $m] >= 0} {
-		merge_load_stages $path [list show_unmerged_diff $scroll_pos]
+		merge_load_stages $path [list show_unmerged_diff $cont_info]
 	} elseif {$m eq {_O}} {
-		show_other_diff $path $w $m $scroll_pos
+		show_other_diff $path $w $m $cont_info
 	} else {
-		start_show_diff $scroll_pos
+		start_show_diff $cont_info
 	}
 }
 
-proc show_unmerged_diff {scroll_pos} {
+proc show_unmerged_diff {cont_info} {
 	global current_diff_path current_diff_side
-	global merge_stages ui_diff
+	global merge_stages ui_diff is_conflict_diff
 	global current_diff_queue
 
 	if {$merge_stages(2) eq {}} {
+		set is_conflict_diff 1
 		lappend current_diff_queue \
 			[list "LOCAL: deleted\nREMOTE:\n" d======= \
 			    [list ":1:$current_diff_path" ":3:$current_diff_path"]]
 	} elseif {$merge_stages(3) eq {}} {
+		set is_conflict_diff 1
 		lappend current_diff_queue \
 			[list "REMOTE: deleted\nLOCAL:\n" d======= \
 			    [list ":1:$current_diff_path" ":2:$current_diff_path"]]
 	} elseif {[lindex $merge_stages(1) 0] eq {120000}
 		|| [lindex $merge_stages(2) 0] eq {120000}
 		|| [lindex $merge_stages(3) 0] eq {120000}} {
+		set is_conflict_diff 1
 		lappend current_diff_queue \
 			[list "LOCAL:\n" d======= \
 			    [list ":1:$current_diff_path" ":2:$current_diff_path"]]
@@ -129,14 +135,14 @@ proc show_unmerged_diff {scroll_pos} {
 			[list "REMOTE:\n" d======= \
 			    [list ":1:$current_diff_path" ":3:$current_diff_path"]]
 	} else {
-		start_show_diff $scroll_pos
+		start_show_diff $cont_info
 		return
 	}
 
-	advance_diff_queue $scroll_pos
+	advance_diff_queue $cont_info
 }
 
-proc advance_diff_queue {scroll_pos} {
+proc advance_diff_queue {cont_info} {
 	global current_diff_queue ui_diff
 
 	set item [lindex $current_diff_queue 0]
@@ -146,10 +152,10 @@ proc advance_diff_queue {scroll_pos} {
 	$ui_diff insert end [lindex $item 0] [lindex $item 1]
 	$ui_diff conf -state disabled
 
-	start_show_diff $scroll_pos [lindex $item 2]
+	start_show_diff $cont_info [lindex $item 2]
 }
 
-proc show_other_diff {path w m scroll_pos} {
+proc show_other_diff {path w m cont_info} {
 	global file_states file_lists
 	global is_3way_diff diff_active repo_config
 	global ui_diff ui_index ui_workdir
@@ -228,16 +234,21 @@ proc show_other_diff {path w m scroll_pos} {
 		$ui_diff conf -state disabled
 		set diff_active 0
 		unlock_index
+		set scroll_pos [lindex $cont_info 0]
 		if {$scroll_pos ne {}} {
 			update
 			$ui_diff yview moveto $scroll_pos
 		}
 		ui_ready
+		set callback [lindex $cont_info 1]
+		if {$callback ne {}} {
+			eval $callback
+		}
 		return
 	}
 }
 
-proc start_show_diff {scroll_pos {add_opts {}}} {
+proc start_show_diff {cont_info {add_opts {}}} {
 	global file_states file_lists
 	global is_3way_diff diff_active repo_config
 	global ui_diff ui_index ui_workdir
@@ -292,12 +303,12 @@ proc start_show_diff {scroll_pos {add_opts {}}} {
 		-blocking 0 \
 		-encoding [get_path_encoding $path] \
 		-translation lf
-	fileevent $fd readable [list read_diff $fd $scroll_pos]
+	fileevent $fd readable [list read_diff $fd $cont_info]
 }
 
-proc read_diff {fd scroll_pos} {
+proc read_diff {fd cont_info} {
 	global ui_diff diff_active
-	global is_3way_diff current_diff_header
+	global is_3way_diff is_conflict_diff current_diff_header
 	global current_diff_queue
 
 	$ui_diff conf -state normal
@@ -345,6 +356,7 @@ proc read_diff {fd scroll_pos} {
 			{--} {set tags d_--}
 			{++} {
 				if {[regexp {^\+\+([<>]{7} |={7})} $line _g op]} {
+					set is_conflict_diff 1
 					set line [string replace $line 0 1 {  }]
 					set tags d$op
 				} else {
@@ -364,6 +376,7 @@ proc read_diff {fd scroll_pos} {
 			{-} {set tags d_-}
 			{+} {
 				if {[regexp {^\+([<>]{7} |={7})} $line _g op]} {
+					set is_conflict_diff 1
 					set line [string replace $line 0 0 { }]
 					set tags d$op
 				} else {
@@ -388,12 +401,13 @@ proc read_diff {fd scroll_pos} {
 		close $fd
 
 		if {$current_diff_queue ne {}} {
-			advance_diff_queue $scroll_pos
+			advance_diff_queue $cont_info
 			return
 		}
 
 		set diff_active 0
 		unlock_index
+		set scroll_pos [lindex $cont_info 0]
 		if {$scroll_pos ne {}} {
 			update
 			$ui_diff yview moveto $scroll_pos
@@ -403,6 +417,10 @@ proc read_diff {fd scroll_pos} {
 		if {[$ui_diff index end] eq {2.0}} {
 			handle_empty_diff
 		}
+		set callback [lindex $cont_info 1]
+		if {$callback ne {}} {
+			eval $callback
+		}
 	}
 }
 
diff --git a/lib/mergetool.tcl b/lib/mergetool.tcl
index a44a7258bc..6ab5701d93 100644
--- a/lib/mergetool.tcl
+++ b/lib/mergetool.tcl
@@ -5,12 +5,6 @@ proc merge_resolve_one {stage} {
 	global current_diff_path
 
 	switch -- $stage {
-		0 {	# Stage without confirmation, to minimize
-			# disruption of the rerere workflow
-			merge_add_resolution $current_diff_path
-			return
-		}
-
 		1 { set targetquestion [mc "Force resolution to the base version?"] }
 		2 { set targetquestion [mc "Force resolution to this branch?"] }
 		3 { set targetquestion [mc "Force resolution to the other branch?"] }
@@ -29,6 +23,33 @@ This operation can be undone only by restarting the merge." \
 	}
 }
 
+proc merge_stage_workdir {path w lno} {
+	global current_diff_path diff_active
+
+	if {$diff_active} return
+
+	if {$path ne $current_diff_path} {
+		show_diff $path $w $lno {} [list do_merge_stage_workdir $path]
+	} else {
+		do_merge_stage_workdir $path
+	}
+}
+
+proc do_merge_stage_workdir {path} {
+	global current_diff_path is_conflict_diff
+
+	if {$path ne $current_diff_path} return;
+
+	if {$is_conflict_diff} {
+		if {[ask_popup [mc "File %s seems to have unresolved conflicts, still stage?" \
+				[short_path $path]]] ne {yes}} {
+			return
+		}
+	}
+
+	merge_add_resolution $path
+}
+
 proc merge_add_resolution {path} {
 	global current_diff_path ui_workdir