git-gui: Allow the user to disable diff stat summary during pull.

Because the pull diffstat summary can take as long as the pull itself
some users may just choose to disable the summary and save themselves
an extra few seconds during each pull.  This is especially true if the
user really doesn't care about the other files being modified, as due
to their project organizational structure they aren't really responsible
for their content.

This adds an option to the options panel which lets the user disable
the diffstat summary (and thus we pass --no-summary to git-pull) but
there does appear to be a bug in the config saving code where we did
not set the local repo config differently from the global config.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

git-gui

@@ -896,8 +896,7 @@ proc fetch_from {remote} {
 }
 
 proc pull_remote {remote branch} {
-	global HEAD commit_type
-	global file_states
+	global HEAD commit_type file_states repo_config
 
 	if {![lock_index update]} return
 
@@ -933,6 +932,9 @@ Commit or throw away all changes before starting a pull operation.
 	set w [new_console "pull $remote $branch" \
 		"Pulling new changes from branch $branch in $remote"]
 	set cmd [list git pull]
+	if {$repo_config(gui.pullsummary) == {false}} {
+		lappend cmd --no-summary
+	}
 	lappend cmd $remote
 	lappend cmd $branch
 	console_exec $w $cmd [list post_pull_remote $remote $branch]
@@ -1760,6 +1762,7 @@ proc do_options {} {
 	pack $w.global -side right -fill both -expand 1 -pady 5 -padx 5
 
 	foreach option {
+		{pullsummary {Show Pull Summary}}
 		{trustmtime {Trust File Modification Timestamps}}
 		} {
 		set name [lindex $option 0]
@@ -1916,6 +1919,7 @@ proc apply_config {} {
 }
 
 set default_config(gui.trustmtime) false
+set default_config(gui.pullsummary) true
 set default_config(gui.fontui) [font configure font_ui]
 set default_config(gui.fontdiff) [font configure font_diff]
 set font_descs {