gitk: Display dirty submodules correctly

Since recently "git diff --submodule" prints out extra lines when the
submodule contains untracked or modified files. Show all those lines of
one submodule under the same header.

Also for newly added or removed submodules the submodule name contained
trailing garbage because the extraction of the name was not done right.

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -7509,7 +7509,7 @@ proc getblobdiffs {ids} {
     global ignorespace
     global limitdiffs vfilelimit curview
     global diffencoding targetline diffnparents
-    global git_version
+    global git_version currdiffsubmod
 
     set textconv {}
     if {[package vcompare $git_version "1.6.1"] >= 0} {
@@ -7536,6 +7536,7 @@ proc getblobdiffs {ids} {
     set diffencoding [get_path_encoding {}]
     fconfigure $bdf -blocking 0 -encoding binary -eofchar {}
     set blobdifffd($ids) $bdf
+    set currdiffsubmod ""
     filerun $bdf [list getblobdiffline $bdf $diffids]
 }
 
@@ -7606,7 +7607,7 @@ proc getblobdiffline {bdf ids} {
     global diffnexthead diffnextnote difffilestart
     global ctext_file_names ctext_file_lines
     global diffinhdr treediffs mergemax diffnparents
-    global diffencoding jump_to_here targetline diffline
+    global diffencoding jump_to_here targetline diffline currdiffsubmod
 
     set nr 0
     $ctext conf -state normal
@@ -7687,19 +7688,30 @@ proc getblobdiffline {bdf ids} {
 
 	} elseif {![string compare -length 10 "Submodule " $line]} {
 	    # start of a new submodule
-	    if {[string compare [$ctext get "end - 4c" end] "\n \n\n"]} {
+	    if {[regexp -indices "\[0-9a-f\]+\\.\\." $line nameend]} {
+		set fname [string range $line 10 [expr [lindex $nameend 0] - 2]]
+	    } else {
+		set fname [string range $line 10 [expr [string first "contains " $line] - 2]]
+	    }
+	    if {$currdiffsubmod != $fname} {
 		$ctext insert end "\n";     # Add newline after commit message
 	    }
 	    set curdiffstart [$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
+	    if {$currdiffsubmod != $fname} {
+		lappend ctext_file_lines $fname
+		makediffhdr $fname $ids
+		set currdiffsubmod $fname
+		$ctext insert end "\n$line\n" filesep
+	    } else {
+		$ctext insert end "$line\n" filesep
+	    }
 	} elseif {![string compare -length 3 "  >" $line]} {
+	    set $currdiffsubmod ""
 	    set line [encoding convertfrom $diffencoding $line]
 	    $ctext insert end "$line\n" dresult
 	} elseif {![string compare -length 3 "  <" $line]} {
+	    set $currdiffsubmod ""
 	    set line [encoding convertfrom $diffencoding $line]
 	    $ctext insert end "$line\n" d0
 	} elseif {$diffinhdr} {
@@ -8535,7 +8547,7 @@ proc do_cmp_commits {a b} {
 }
 
 proc diffcommits {a b} {
-    global diffcontext diffids blobdifffd diffinhdr
+    global diffcontext diffids blobdifffd diffinhdr currdiffsubmod
 
     set tmpdir [gitknewtmpdir]
     set fna [file join $tmpdir "commit-[string range $a 0 7]"]
@@ -8556,6 +8568,7 @@ proc diffcommits {a b} {
     set diffids [list commits $a $b]
     set blobdifffd($diffids) $fd
     set diffinhdr 0
+    set currdiffsubmod ""
     filerun $fd [list getblobdiffline $fd $diffids]
 }