[PATCH] gitk: Use the --submodule option for diffs

[Jens Lehmann <Jens.Lehmann@web.de>]

Instead of just showing not-quite-helpful SHA-1 pairs display the first
lines of the corresponding commit messages in the submodule (similar to
the output of 'git submodule summary').

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
---

This patch applies to 'next' and uses the new --submodule option of git
diff to achieve a more meaningful output of submodule differences in
gitk.

Any objections against making this the default?

(for those interested: a version of git gui with similar functionality
is available in 'master' of Shawn's repo but not yet merged).


 gitk-git/gitk |   23 +++++++++++++++++++----
 1 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/gitk-git/gitk b/gitk-git/gitk
index a0214b7..5e2572d 100644
--- a/gitk-git/gitk
+++ b/gitk-git/gitk
@@ -7207,7 +7207,7 @@ proc diffcmd {ids flags} {
     if {$i >= 0} {
 	if {[llength $ids] > 1 && $j < 0} {
 	    # comparing working directory with some specific revision
-	    set cmd [concat | git diff-index $flags]
+	    set cmd [concat | git diff-index --submodule $flags]
 	    if {$i == 0} {
 		lappend cmd -R [lindex $ids 1]
 	    } else {
@@ -7215,13 +7215,13 @@ proc diffcmd {ids flags} {
 	    }
 	} else {
 	    # comparing working directory with index
-	    set cmd [concat | git diff-files $flags]
+	    set cmd [concat | git diff-files --submodule $flags]
 	    if {$j == 1} {
 		lappend cmd -R
 	    }
 	}
     } elseif {$j >= 0} {
-	set cmd [concat | git diff-index --cached $flags]
+	set cmd [concat | git diff-index --cached --submodule $flags]
 	if {[llength $ids] > 1} {
 	    # comparing index with specific revision
 	    if {$i == 0} {
@@ -7234,7 +7234,7 @@ proc diffcmd {ids flags} {
 	    lappend cmd HEAD
 	}
     } else {
-	set cmd [concat | git diff-tree -r $flags $ids]
+	set cmd [concat | git diff-tree -r --submodule $flags $ids]
     }
     return $cmd
 }
@@ -7481,6 +7481,21 @@ proc getblobdiffline {bdf ids} {
 	    set diffnparents [expr {[string length $ats] - 1}]
 	    set diffinhdr 0

+	} elseif {![string compare -length 10 "Submodule " $line]} {
+	    # start of a new submodule
+	    if {[string compare [$ctext get "end - 4c" end] "\n \n\n"]} {
+		$ctext insert end "\n";     # Add newline after commit message
+	    }
+	    set curdiffstart [$ctext index "end - 1c"]
+	    lappend ctext_file_names ""
+	    set fname [string range $line 10 [expr [string last " " $line] - 1]]
+	    lappend ctext_file_lines $fname
+	    makediffhdr $fname $ids
+	    $ctext insert end "\n$line\n" filesep
+	} elseif {![string compare -length 3 "  >" $line]} {
+	    $ctext insert end "$line\n" dresult
+	} elseif {![string compare -length 3 "  <" $line]} {
+	    $ctext insert end "$line\n" d0
 	} elseif {$diffinhdr} {
 	    if {![string compare -length 12 "rename from " $line]} {
 		set fname [string range $line [expr 6 + [string first " from " $line] ] end]
-- 
1.6.5.2.182.g338ab.dirty