git-gui: Implement automatic rescan after Tool execution.

The Tools menu is generally intended for commands that
affect the working directory or repository state. Thus,
the user would usually want to initiate rescan after
execution of a tool. This commit implements it.

In case somebody would want to avoid rescanning after
certain tools, it also adds an option that controls it,
although it is not made available through the Add dialog.

Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Author: angavrilov

lib/tools.tcl

@@ -102,13 +102,15 @@ proc tools_exec {fullname} {
 
 	set cmdline $repo_config(guitool.$fullname.cmd)
 	if {[is_config_true "guitool.$fullname.noconsole"]} {
-		exec sh -c $cmdline &
+		tools_run_silent [list sh -c $cmdline] \
+				 [list tools_complete $fullname {}]
 	} else {
 		regsub {/} $fullname { / } title
 		set w [console::new \
 			[mc "Tool: %s" $title] \
 			[mc "Running: %s" $cmdline]]
-		console::exec $w [list sh -c $cmdline]
+		console::exec $w [list sh -c $cmdline] \
+				 [list tools_complete $fullname $w]
 	}
 
 	unset env(GIT_GUITOOL)
@@ -117,3 +119,41 @@ proc tools_exec {fullname} {
 	catch { unset env(ARGS) }
 	catch { unset env(REVISION) }
 }
+
+proc tools_run_silent {cmd after} {
+	lappend cmd 2>@1
+	set fd [_open_stdout_stderr $cmd]
+
+	fconfigure $fd -blocking 0 -translation binary
+	fileevent $fd readable [list tools_consume_input $fd $after]
+}
+
+proc tools_consume_input {fd after} {
+	read $fd
+	if {[eof $fd]} {
+		fconfigure $fd -blocking 1
+		if {[catch {close $fd}]} {
+			uplevel #0 $after 0
+		} else {
+			uplevel #0 $after 1
+		}
+	}
+}
+
+proc tools_complete {fullname w {ok 1}} {
+	if {$w ne {}} {
+		console::done $w $ok
+	}
+
+	if {$ok} {
+		set msg [mc "Tool completed succesfully: %s" $fullname]
+	} else {
+		set msg [mc "Tool failed: %s" $fullname]
+	}
+
+	if {[is_config_true "guitool.$fullname.norescan"]} {
+		ui_status $msg
+	} else {
+		rescan [list ui_status $msg]
+	}
+}