[PATCH 2/2] git-gui: support for diff3 conflict style

[Bert Wesarg]

This adds highlight support for the diff3 conflict style.

The common pre-image will be reversed to --, because it has been removed
and either replaced with ours or theirs side.

Signed-off-by: Bert Wesarg <bert.wes...@googlemail.com>
---
 git-gui.sh   |  3 +++
 lib/diff.tcl | 22 ++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/git-gui.sh b/git-gui.sh
index fd476b6..6d80f82 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -3581,6 +3581,9 @@ $ui_diff tag conf d_s- \
 $ui_diff tag conf d< \
        -foreground orange \
        -font font_diffbold
+$ui_diff tag conf d| \
+       -foreground orange \
+       -font font_diffbold
 $ui_diff tag conf d= \
        -foreground orange \
        -font font_diffbold
diff --git a/lib/diff.tcl b/lib/diff.tcl
index 0fd4600..6caf4e7 100644
--- a/lib/diff.tcl
+++ b/lib/diff.tcl
@@ -347,6 +347,7 @@ proc start_show_diff {cont_info {add_opts {}}} {
        }
 
        set ::current_diff_inheader 1
+       set ::conflict_state {CONTEXT}
        fconfigure $fd \
                -blocking 0 \
                -encoding [get_path_encoding $path] \
@@ -450,10 +451,28 @@ proc read_diff {fd conflict_size cont_info} {
                        {++} {
                                set regexp [string map [list %conflict_size 
$conflict_size]\
                                                                
{^\+\+([<>=]){%conflict_size}(?: |$)}]
+                               set regexp_pre_image [string map [list 
%conflict_size $conflict_size]\
+                                                               
{^\+\+\|{%conflict_size}(?: |$)}]
                                if {[regexp $regexp $line _g op]} {
                                        set is_conflict_diff 1
                                        set line [string replace $line 0 1 {  }]
+                                       set markup {}
                                        set tags d$op
+                                       switch -exact -- $op {
+                                       < { set ::conflict_state {OURS} }
+                                       = { set ::conflict_state {THEIRS} }
+                                       > { set ::conflict_state {CONTEXT} }
+                                       }
+                               } elseif {[regexp $regexp_pre_image $line]} {
+                                       set is_conflict_diff 1
+                                       set line [string replace $line 0 1 {  }]
+                                       set markup {}
+                                       set tags d|
+                                       set ::conflict_state {BASE}
+                               } elseif {$::conflict_state eq {BASE}} {
+                                       set line [string replace $line 0 1 {--}]
+                                       set markup {}
+                                       set tags d_--
                                } else {
                                        set tags d_++
                                }
@@ -505,6 +524,9 @@ proc read_diff {fd conflict_size cont_info} {
                        }
                }
                set mark [$ui_diff index "end - 1 line linestart"]
+               if {[llength $markup] > 0} {
+                       set tags {}
+               }
                $ui_diff insert end $line $tags
                if {[string index $line end] eq "\r"} {
                        $ui_diff tag add d_cr {end - 2c}
-- 
2.21.0.789.ga095d9d866