--- sndhdr.py.orig	2008-09-16 13:21:41.000000000 +0200
+++ /usr/lib/python2.5/sndhdr.py	2008-09-16 13:38:35.000000000 +0200
@@ -126,15 +126,38 @@
 
 tests.append(test_voc)
 
+# This list of chunk types and parts of below code are based on the WAV
+# description at
+# http://www.sonicspot.com/guide/wavefiles.html#wavefileheader
+# bext and fake are taken from a file found at
+# http://bugs.python.org/issue1611944
+chunk_types = ['fmt ', 'data', 'fact', 'wavl', 'sint', 'cue ', 'plst',
+               'list', 'labl', 'note', 'ltxt', 'smpl', 'inst', 'bext', 'fake']
 
 def test_wav(h, f):
     # 'RIFF' <len> 'WAVE' 'fmt ' <len>
-    if h[:4] != 'RIFF' or h[8:12] != 'WAVE' or h[12:16] != 'fmt ':
+    if h[:4] != 'RIFF' or h[8:12] != 'WAVE':
         return None
-    style = get_short_le(h[20:22])
-    nchannels = get_short_le(h[22:24])
-    rate = get_long_le(h[24:28])
-    sample_bits = get_short_le(h[34:36])
+    offset = 12
+    
+    # Now, look for the first fmt chunk. Chunks start with two fields,
+    # one for chunk type and one for chunk length.
+    while (h[offset:offset+4].lower() != 'fmt '):
+        # This check and the chunk_types variable above should probably
+        # be removed
+        if (not h[offset:offset+4].lower() in chunk_types):
+            # Wrong header? Probably not a wave file after all
+            return None
+        offset = offset + ( get_long_le( h[offset+4:offset+8] ) + 8 )
+        # We need to read at least 24 bytes from offset to find the fmt
+        # info
+        if offset + 24 > len(h):
+            return 
+
+    style = get_short_le(h[offset+8:offset+10])
+    nchannels = get_short_le(h[offset+10:offset+12])
+    rate = get_long_le(h[offset+12:offset+16])
+    sample_bits = get_short_le(h[offset+22:offset+24])
     return 'wav', rate, nchannels, -1, sample_bits
 
 tests.append(test_wav)