From 6a0d21acca616aa4cf11468e3dc6f1c052e1d94f Mon Sep 17 00:00:00 2001
From: ppatience0 <ppatience0@gmail.com>
Date: Mon, 27 May 2013 00:26:19 -0400
Subject: [PATCH] mothra: clicking on the url scroll bar, snarfing, or saving a
 hit when no urls have been loaded (right after running mothra) would crash.
 this was due to use of w->url and selection when they are actually nil.

to fix this, make genwww return 0 if w->url is nil and output an error message when attempting to access selection if it's nil. the problem with the w->url fix is that after clicking on the url scroll bar, an empty url history row could be highlighted by clicking on it. fix this by making sure lp->lo is not less than zero.
---
 sys/src/cmd/mothra/libpanel/list.c |  2 +-
 sys/src/cmd/mothra/mothra.c        | 13 +++++++++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/sys/src/cmd/mothra/libpanel/list.c b/sys/src/cmd/mothra/libpanel/list.c
index fb9b676f7..8f4b0766f 100644
--- a/sys/src/cmd/mothra/libpanel/list.c
+++ b/sys/src/cmd/mothra/libpanel/list.c
@@ -22,7 +22,7 @@ void pl_listsel(Panel *p, int sel, int on){
 	Rectangle r;
 	lp=p->data;
 	hi=lp->lo+(lp->listr.max.y-lp->listr.min.y)/font->height;
-	if(lp->lo<=sel && sel<hi && sel<lp->len){
+	if(lp->lo>=0 && lp->lo<=sel && sel<hi && sel<lp->len){
 		r=lp->listr;
 		r.min.y+=(sel-lp->lo)*font->height;
 		r.max.y=r.min.y+font->height;
diff --git a/sys/src/cmd/mothra/mothra.c b/sys/src/cmd/mothra/mothra.c
index d1d06abe3..79e6191d2 100644
--- a/sys/src/cmd/mothra/mothra.c
+++ b/sys/src/cmd/mothra/mothra.c
@@ -484,6 +484,8 @@ char *genwww(Panel *, int index){
 		return 0;
 	i = wwwtop-index-1;
 	w = www(i);
+	if(!w->url)
+		return 0;
 	if(w->title[0]!='\0'){
 		w->gottitle=1;
 		snprint(buf, sizeof(buf), "%2d %s", i+1, w->title);
@@ -1027,8 +1029,11 @@ void killpix(Www *w){
 }
 void snarf(Panel *p){
 	if(p==0 || p==cmd){
-		plputsnarf(urlstr(selection));
-		plsnarf(text);
+		if(selection){
+			plputsnarf(urlstr(selection));
+			plsnarf(text);
+		}else
+			message("no url selected");
 	}else
 		plsnarf(p);
 }
@@ -1070,6 +1075,10 @@ void hit3(int button, int item){
 		paste(plkbfocus);
 		break;
 	case 4:
+		if(!selection){
+			message("no url selected");
+			break;
+		}
 		snprint(name, sizeof(name), "%s/hit.html", home);
 		fd=open(name, OWRITE);
 		if(fd==-1){