From b479ece7b488e236418014f9dd1ff5db1877b522 Mon Sep 17 00:00:00 2001
From: John Evans <jevans@nmr.mgh.harvard.edu>
Date: Wed, 12 Mar 2014 10:10:38 -0400
Subject: [PATCH] Bring back check for bad rlevel.  #159

OpenJPEG 1.5 needs the protection, it would seem.
---
 glymur/jp2k.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/glymur/jp2k.py b/glymur/jp2k.py
index 3467426..7a513fe 100644
--- a/glymur/jp2k.py
+++ b/glymur/jp2k.py
@@ -772,6 +772,19 @@ class Jp2k(Jp2kBox):
         """
         self._subsampling_sanity_check()
 
+        # Must check the specified rlevel against the maximum.
+        if rlevel != 0:
+            # Must check the specified rlevel against the maximum.
+            codestream = self.get_codestream()
+            max_rlevel = codestream.segment[2].spcod[4]
+            if rlevel == -1:
+                # -1 is shorthand for the largest rlevel
+                rlevel = max_rlevel
+            elif rlevel < -1 or rlevel > max_rlevel:
+                    msg = "rlevel must be in the range [-1, {0}] for this image."
+                    msg = msg.format(max_rlevel)
+                    raise IOError(msg)
+
         with ExitStack() as stack:
             try:
                 # Set decoding parameters.