git-gui: use textconv filter for diff and blame

Create a checkbox "Use Textconv For Diffs and Blame" in git-gui options.
If checked and if the driver for the concerned file exists, git-gui calls diff
and blame with --textconv option

Signed-off-by: Clément Poulain <clement.poulain@ensimag.imag.fr>
Signed-off-by: Diane Gasselin <diane.gasselin@ensimag.imag.fr>
Signed-off-by: Axel Bonnet <axel.bonnet@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>

git-gui.sh

@@ -269,6 +269,17 @@ proc is_config_true {name} {
 	}
 }
 
+proc is_config_false {name} {
+	global repo_config
+	if {[catch {set v $repo_config($name)}]} {
+		return 0
+	} elseif {$v eq {false} || $v eq {0} || $v eq {no}} {
+		return 1
+	} else {
+		return 0
+	}
+}
+
 proc get_config {name} {
 	global repo_config
 	if {[catch {set v $repo_config($name)}]} {
@@ -785,6 +796,7 @@ set default_config(user.email) {}
 
 set default_config(gui.encoding) [encoding system]
 set default_config(gui.matchtrackingbranch) false
+set default_config(gui.textconv) true
 set default_config(gui.pruneduringfetch) false
 set default_config(gui.trustmtime) false
 set default_config(gui.fastcopyblame) false
@@ -3411,6 +3423,19 @@ lappend diff_actions [list $ctxmsm entryconf [$ctxmsm index last] -state]
 $ctxmsm add separator
 create_common_diff_popup $ctxmsm
 
+proc has_textconv {path} {
+	if {[is_config_false gui.textconv]} {
+		return 0
+	}
+	set filter [gitattr $path diff set]
+	set textconv [get_config [join [list diff $filter textconv] .]]
+	if {$filter ne {set} && $textconv ne {}} {
+		return 1
+	} else {
+		return 0
+	}
+}
+
 proc popup_diff_menu {ctxm ctxmmg ctxmsm x y X Y} {
 	global current_diff_path file_states
 	set ::cursorX $x
@@ -3446,7 +3471,8 @@ proc popup_diff_menu {ctxm ctxmmg ctxmsm x y X Y} {
 			|| {__} eq $state
 			|| {_O} eq $state
 			|| {_T} eq $state
-			|| {T_} eq $state} {
+			|| {T_} eq $state
+			|| [has_textconv $current_diff_path]} {
 			set s disabled
 		} else {
 			set s normal

lib/blame.tcl

@@ -449,11 +449,28 @@ method _load {jump} {
 
 	$status show [mc "Reading %s..." "$commit:[escape_path $path]"]
 	$w_path conf -text [escape_path $path]
+
+	set do_textconv 0
+	if {![is_config_false gui.textconv] && [git-version >= 1.7.2]} {
+		set filter [gitattr $path diff set]
+		set textconv [get_config [join [list diff $filter textconv] .]]
+		if {$filter ne {set} && $textconv ne {}} {
+			set do_textconv 1
+		}
+	}
 	if {$commit eq {}} {
-		set fd [open $path r]
+		if {$do_textconv ne 0} {
+			set fd [open |[list $textconv $path] r]
+		} else {
+			set fd [open $path r]
+		}
 		fconfigure $fd -eofchar {}
 	} else {
-		set fd [git_read cat-file blob "$commit:$path"]
+		if {$do_textconv ne 0} {
+			set fd [git_read cat-file --textconv "$commit:$path"]
+		} else {
+			set fd [git_read cat-file blob "$commit:$path"]
+		}
 	}
 	fconfigure $fd \
 		-blocking 0 \

lib/diff.tcl

@@ -55,7 +55,7 @@ proc handle_empty_diff {} {
 
 	set path $current_diff_path
 	set s $file_states($path)
-	if {[lindex $s 0] ne {_M}} return
+	if {[lindex $s 0] ne {_M} || [has_textconv $path]} return
 
 	# Prevent infinite rescan loops
 	incr diff_empty_count
@@ -280,6 +280,9 @@ proc start_show_diff {cont_info {add_opts {}}} {
 			lappend cmd diff-files
 		}
 	}
+	if {![is_config_false gui.textconv] && [git-version >= 1.6.1]} {
+		lappend cmd --textconv
+	}
 
 	if {[string match {160000 *} [lindex $s 2]]
 	 || [string match {160000 *} [lindex $s 3]]} {

lib/option.tcl

@@ -148,6 +148,7 @@ proc do_options {} {
 		{b gui.trustmtime  {mc "Trust File Modification Timestamps"}}
 		{b gui.pruneduringfetch {mc "Prune Tracking Branches During Fetch"}}
 		{b gui.matchtrackingbranch {mc "Match Tracking Branches"}}
+		{b gui.textconv {mc "Use Textconv For Diffs and Blames"}}
 		{b gui.fastcopyblame {mc "Blame Copy Only On Changed Files"}}
 		{i-20..200 gui.copyblamethreshold {mc "Minimum Letters To Blame Copy On"}}
 		{i-0..300 gui.blamehistoryctx {mc "Blame History Context Radius (days)"}}