patch by Daniel Blueman for Bug 590079

diff --git a/share/extensions/funcplot.py b/share/extensions/funcplot.py
index e5f93d4309eab1cd91f7b39fc60d83930853f69d..1264298532fd574fc81c57776e700803449a61ea 100644 (file)
--- a/share/extensions/funcplot.py
+++ b/share/extensions/funcplot.py
@@ -70,10 +70,14 @@ def drawfunction(xstart, xend, ybottom, ytop, samples, width, height, left, bott
         ytop = (bottom+height-yzero)/scaley
 
     # functions specified by the user
-    if fx != "":
-        f = eval('lambda x: ' + fx.strip('"'))
-    if fpx != "":
-        fp = eval('lambda x: ' + fpx.strip('"'))
+    try:
+        if fx != "":
+            f = eval('lambda x: ' + fx.strip('"'))
+        if fpx != "":
+            fp = eval('lambda x: ' + fpx.strip('"'))
+    # handle incomplete/invalid function gracefully
+    except SyntaxError:
+        return []
 
     # step is the distance between nodes on x
     step = (xend - xstart) / (samples-1)