From fcd3e6ce00d828b1f3c71a756865fea41dc9d4bf Mon Sep 17 00:00:00 2001
From: Sebastian Schuberth <sschuberth@gmail.com>
Date: Wed, 18 Oct 2017 17:49:42 +0200
Subject: [PATCH] Catch an error unpack might throw instead of checking the
 length before

---
 pdfminer/pdffont.py | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/pdfminer/pdffont.py b/pdfminer/pdffont.py
index 99f7811..feb8557 100644
--- a/pdfminer/pdffont.py
+++ b/pdfminer/pdffont.py
@@ -383,16 +383,16 @@ class TrueTypeFont(object):
         self.fp = fp
         self.tables = {}
         self.fonttype = fp.read(4)
-        data_str = fp.read(8)
-        if len(data_str) != 8:
-            return
-        (ntables, _1, _2, _3) = struct.unpack('>HHHH', data_str)
-        for _ in range(ntables):
-            data_str = fp.read(16)
-            if len(data_str) != 16:
-                return
-            (name, tsum, offset, length) = struct.unpack('>4sLLL', data_str)
-            self.tables[name] = (offset, length)
+        try:
+            (ntables, _1, _2, _3) = struct.unpack('>HHHH', fp.read(8))
+            for _ in range(ntables):
+                (name, tsum, offset, length) = struct.unpack('>4sLLL', fp.read(16))
+                self.tables[name] = (offset, length)
+        except struct.error:
+            # Do not fail if there are not enough bytes to read. Even for
+            # corrupted PDFs we would like to get as much information as
+            # possible, so continue.
+            pass
         return
 
     def create_unicode_map(self):