From e8b0cd1f9ddab45649f9cd5cd2267f05e7df9add Mon Sep 17 00:00:00 2001
From: Jonathan Westhues <jwesthues@cq.cx>
Date: Sun, 10 Jan 2010 16:44:11 -0800
Subject: [PATCH] Oops, don't allow the user to type a zero or negative scale
 in the view screen.

[git-p4: depot-paths = "//depot/solvespace/": change = 2104]
---
 view.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/view.cpp b/view.cpp
index 76a972d..d01a612 100644
--- a/view.cpp
+++ b/view.cpp
@@ -62,7 +62,12 @@ bool TextWindow::EditControlDoneForView(char *s) {
         case EDIT_VIEW_SCALE: {
             Expr *e = Expr::From(s, true);
             if(e) {
-                SS.GW.scale = e->Eval() / SS.MmPerUnit();
+                double v =  e->Eval() / SS.MmPerUnit();
+                if(v > LENGTH_EPS) {
+                    SS.GW.scale = v;
+                } else {
+                    Error("Scale cannot be zero or negative.");
+                }
             }
             break;
         }