git-gui: respect conflict marker size

Respect the conflict-marker-size attribute on paths when detecting merge
conflicts.

[PT: fixed problem with variable substitution in the regexps]

Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>

git-gui.sh

@@ -3351,13 +3351,13 @@ $ui_diff tag conf d_s- \
 	-foreground red \
 	-background ivory1
 
-$ui_diff tag conf d<<<<<<< \
+$ui_diff tag conf d< \
 	-foreground orange \
 	-font font_diffbold
-$ui_diff tag conf d======= \
+$ui_diff tag conf d= \
 	-foreground orange \
 	-font font_diffbold
-$ui_diff tag conf d>>>>>>> \
+$ui_diff tag conf d> \
 	-foreground orange \
 	-font font_diffbold
 

lib/diff.tcl

@@ -253,6 +253,19 @@ proc show_other_diff {path w m cont_info} {
 	}
 }
 
+proc get_conflict_marker_size {path} {
+	set size 7
+	catch {
+		set fd_rc [eval [list git_read check-attr "conflict-marker-size" -- $path]]
+		set ret [gets $fd_rc line]
+		close $fd_rc
+		if {$ret > 0} {
+			regexp {.*: conflict-marker-size: (\d+)$} $line line size
+		}
+	}
+	return $size
+}
+
 proc start_show_diff {cont_info {add_opts {}}} {
 	global file_states file_lists
 	global is_3way_diff is_submodule_diff diff_active repo_config
@@ -268,6 +281,7 @@ proc start_show_diff {cont_info {add_opts {}}} {
 	set is_submodule_diff 0
 	set diff_active 1
 	set current_diff_header {}
+	set conflict_size [get_conflict_marker_size $path]
 
 	set cmd [list]
 	if {$w eq $ui_index} {
@@ -329,7 +343,7 @@ proc start_show_diff {cont_info {add_opts {}}} {
 		-blocking 0 \
 		-encoding [get_path_encoding $path] \
 		-translation lf
-	fileevent $fd readable [list read_diff $fd $cont_info]
+	fileevent $fd readable [list read_diff $fd $conflict_size $cont_info]
 }
 
 proc parse_color_line {line} {
@@ -357,7 +371,7 @@ proc parse_color_line {line} {
 	return [list $result $markup]
 }
 
-proc read_diff {fd cont_info} {
+proc read_diff {fd conflict_size cont_info} {
 	global ui_diff diff_active is_submodule_diff
 	global is_3way_diff is_conflict_diff current_diff_header
 	global current_diff_queue
@@ -410,7 +424,9 @@ proc read_diff {fd cont_info} {
 			{- } {set tags d_-s}
 			{--} {set tags d_--}
 			{++} {
-				if {[regexp {^\+\+([<>]{7} |={7})} $line _g op]} {
+				set regexp [string map [list %conflict_size $conflict_size]\
+								{^\+\+([<>=]){%conflict_size}(?: |$)}]
+				if {[regexp $regexp $line _g op]} {
 					set is_conflict_diff 1
 					set line [string replace $line 0 1 {  }]
 					set tags d$op
@@ -449,7 +465,9 @@ proc read_diff {fd cont_info} {
 			{@} {set tags d_@}
 			{-} {set tags d_-}
 			{+} {
-				if {[regexp {^\+([<>]{7} |={7})} $line _g op]} {
+				set regexp [string map [list %conflict_size $conflict_size]\
+								{^\+([<>=]){%conflict_size}(?: |$)}]
+				if {[regexp $regexp $line _g op]} {
 					set is_conflict_diff 1
 					set tags d$op
 				} else {