From 1fc9086050abe372a5db4c1a076e7f61a99b3642 Mon Sep 17 00:00:00 2001
From: Sambhav Kothari <sambhavs.email@gmail.com>
Date: Fri, 30 Dec 2016 03:57:57 +0530
Subject: [PATCH] PICARD-834: Properly handle ValueErrors in case of invalid
 length attribute

---
 picard/script.py | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/picard/script.py b/picard/script.py
index 0d341dcb1..630e0da19 100644
--- a/picard/script.py
+++ b/picard/script.py
@@ -332,12 +332,18 @@ def func_noop(parser, *args):
 
 def func_left(parser, text, length):
     """Returns first ``num`` characters from ``text``."""
-    return text[:int(length)]
+    try:
+        return text[:int(length)]
+    except ValueError:
+        return ""
 
 
 def func_right(parser, text, length):
     """Returns last ``num`` characters from ``text``."""
-    return text[-int(length):]
+    try:
+        return text[-int(length):]
+    except ValueError:
+        return ""
 
 
 def func_lower(parser, text):
@@ -351,7 +357,10 @@ def func_upper(parser, text):
 
 
 def func_pad(parser, text, length, char):
-    return char * (int(length) - len(text)) + text
+    try:
+        return char * (int(length) - len(text)) + text
+    except ValueError:
+        return ""
 
 
 def func_strip(parser, text):
@@ -389,7 +398,10 @@ def func_rsearch(parser, text, pattern):
 
 
 def func_num(parser, text, length):
-    format = "%%0%dd" % int(length)
+    try:
+        format = "%%0%dd" % int(length)
+    except ValueError:
+        return ""
     try:
         value = int(text)
     except ValueError: