Invalid comparison between string and number for viewbox determination in eggbot.py #11
Description
Reported by Matthew Beckler as https://code.google.com/p/eggbotcode/issues/detail?id=74
Here is the code section:
# Viewbox handling
# Also ignores the preserveAspectRatio attribute
viewbox = self.svg.get( 'viewBox' )
if viewbox:
vinfo = viewbox.strip().replace( ',', ' ' ).split( ' ' )
if ( vinfo[2] != 0 ) and ( vinfo[3] != 0 ): # <-------------------------- this line here ------------<<
sx = self.svgWidth / float( vinfo[2] )
sy = self.svgHeight / float( vinfo[3] )
self.svgTransform = parseTransform( 'scale(%f,%f) translate(%f,%f)' % (sx, sy, -float( vinfo[0] ), -float( vinfo[1] ) ) )
The issue lies with the "if ( vinfo[2] != 0 ) and ( vinfo[3] != 0 ):" line. vinfo is a list of strings, and a comparison is being done to see if two of these strings are not equal to the numeric value 0. Even if the string value in vinfo[2] or vinfo[3] is "0", that is never equal to the numeric value 0 in an inequality check like this. That is, (vinfo[2] != 0) always evaluates to True, because every string is not equal to 0.
I think we should probably wrap vinfo[2] and vinfo[3] in calls to float, making that line instead be:
if ( float(vinfo[2]) != 0 ) and ( float(vinfo[3]) != 0 ):
Again, this probably never causes trouble but is an easy fix. Here's a very small patch for it:
--- eggbot.py 2014-03-21 10:05:49.222832100 -0500
+++ eggbot_fix.py 2014-03-21 10:06:27.758685300 -0500
@@ -526,7 +526,7 @@
viewbox = self.svg.get( 'viewBox' )
if viewbox:
vinfo = viewbox.strip().replace( ',', ' ' ).split( ' ' )
- if ( vinfo[2] != 0 ) and ( vinfo[3] != 0 ):
+ if ( float(vinfo[2]) != 0 ) and ( float(vinfo[3]) != 0 ):
sx = self.svgWidth / float( vinfo[2] )
sy = self.svgHeight / float( vinfo[3] )
self.svgTransform = parseTransform( 'scale(%f,%f) translate(%f,%f)' % (sx, sy, -float( vinfo[0] ), -float( vinfo[1] ) ) )
Alternatively, we could just use map to cast all the entries of vinfo into floats right away, and remove the float calls from the lines afterward:
--- eggbot.py 2014-03-21 10:05:49.222832100 -0500
+++ eggbot_fix_2.py 2014-03-21 10:14:22.526157300 -0500
@@ -525,11 +525,11 @@
# Also ignores the preserveAspectRatio attribute
viewbox = self.svg.get( 'viewBox' )
if viewbox:
- vinfo = viewbox.strip().replace( ',', ' ' ).split( ' ' )
+ vinfo = map(float, viewbox.strip().replace( ',', ' ' ).split( ' ' )) # convert all items to float
if ( vinfo[2] != 0 ) and ( vinfo[3] != 0 ):
- sx = self.svgWidth / float( vinfo[2] )
- sy = self.svgHeight / float( vinfo[3] )
- self.svgTransform = parseTransform( 'scale(%f,%f) translate(%f,%f)' % (sx, sy, -float( vinfo[0] ), -float( vinfo[1] ) ) )
+ sx = self.svgWidth / vinfo[2]
+ sy = self.svgHeight / vinfo[3]
+ self.svgTransform = parseTransform( 'scale(%f,%f) translate(%f,%f)' % (sx, sy, -vinfo[0], -vinfo[1]) )
self.ServoSetup()