Fix for cases whee the coordinate precision is decreased.

If we parse a file with 5.5 INCH format and ask to write
it back as 2.4 INCH we are going to loose precision and
write_gerber_value was not handling these cases write.

1 files changed, 5 insertions, 2 deletions

diff --git a/gerber/utils.py b/gerber/utils.py
index 0f0c07c..64cd6ed 100644
--- a/gerber/utils.py
+++ b/gerber/utils.py
@@ -140,12 +140,15 @@ def write_gerber_value(value, format=(2, 5), zero_suppression='trailing'):
 
     # Suppression...
     if zero_suppression == 'trailing':
-        while digits[-1] == '0':
+        while digits and digits[-1] == '0':
             digits.pop()
     else:
-        while digits[0] == '0':
+        while digits and digits[0] == '0':
             digits.pop(0)
 
+    if not digits:
+        return '0'
+
     return ''.join(digits) if not negative else ''.join(['-'] + digits)