git-gui: Automatically reopen any console closed by the user.

If the user closes a console and we get more ouptut for it then we
will get a Tcl error in the readable event handle for the file channel.
Since this loses the actual output and is quite unfriendly to the end
user instead reopen any console which the user closed prior to the
additional output arriving.
 
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

git-gui

@@ -1005,14 +1005,20 @@ proc hook_failed_popup {hook msg} {
 set next_console_id 0
 
 proc new_console {short_title long_title} {
-	global next_console_id console_cr
+	global next_console_id console_data
+	set w .console[incr next_console_id]
+	set console_data($w) [list $short_title $long_title]
+	return [console_init $w]
+}
+
+proc console_init {w} {
+	global console_cr console_data
 	global gitdir appname mainfont difffont
 
-	set w .console[incr next_console_id]
 	set console_cr($w) 1.0
 	toplevel $w
 	frame $w.m
-	label $w.m.l1 -text "$long_title:" \
+	label $w.m.l1 -text "[lindex $console_data($w) 1]:" \
 		-anchor w \
 		-justify left \
 		-font [concat $mainfont bold]
@@ -1041,8 +1047,7 @@ proc new_console {short_title long_title} {
 	pack $w.ok -side bottom
 
 	bind $w <Visibility> "focus $w"
-	bind $w <Destroy> break
-	wm title $w "$appname ([file dirname [file normalize [file dirname $gitdir]]]): $short_title"
+	wm title $w "$appname ([file dirname [file normalize [file dirname $gitdir]]]): [lindex $console_data($w) 0]"
 	return $w
 }
 
@@ -1067,10 +1072,12 @@ proc console_exec {w cmd} {
 }
 
 proc console_read {w fd} {
-	global console_cr
+	global console_cr console_data
 
-	$w.m.t conf -state normal
 	set buf [read $fd]
+	if {$buf != {}} {
+		if {![winfo exists $w]} {console_init $w}
+		$w.m.t conf -state normal
 		set c 0
 		set n [string length $buf]
 		while {$c < $n} {
@@ -1094,17 +1101,22 @@ proc console_read {w fd} {
 		}
 		$w.m.t conf -state disabled
 		$w.m.t see end
+	}
 
 	fconfigure $fd -blocking 1
 	if {[eof $fd]} {
 		if {[catch {close $fd}]} {
+			if {![winfo exists $w]} {console_init $w}
 			$w.m.s conf -background red -text {Error: Command Failed}
-		} else {
+			$w.ok conf -text Close
+			$w.ok conf -state normal
+		} elseif {[winfo exists $w]} {
 			$w.m.s conf -background green -text {Success}
-		}
 			$w.ok conf -text Close
 			$w.ok conf -state normal
+		}
 		array unset console_cr $w
+		array unset console_data $w
 		return
 	}
 	fconfigure $fd -blocking 0