bpo-32056: Improve exceptions in aifc, wave and sunau. (GH-5951)

1 files changed, 12 insertions, 2 deletions

diff --git a/Lib/wave.py b/Lib/wave.py
index cf94d5a..f155879 100644
--- a/Lib/wave.py
+++ b/Lib/wave.py
@@ -253,12 +253,22 @@ class Wave_read:
     #
 
     def _read_fmt_chunk(self, chunk):
-        wFormatTag, self._nchannels, self._framerate, dwAvgBytesPerSec, wBlockAlign = struct.unpack_from('<HHLLH', chunk.read(14))
+        try:
+            wFormatTag, self._nchannels, self._framerate, dwAvgBytesPerSec, wBlockAlign = struct.unpack_from('<HHLLH', chunk.read(14))
+        except struct.error:
+            raise EOFError from None
         if wFormatTag == WAVE_FORMAT_PCM:
-            sampwidth = struct.unpack_from('<H', chunk.read(2))[0]
+            try:
+                sampwidth = struct.unpack_from('<H', chunk.read(2))[0]
+            except struct.error:
+                raise EOFError from None
             self._sampwidth = (sampwidth + 7) // 8
+            if not self._sampwidth:
+                raise Error('bad sample width')
         else:
             raise Error('unknown format: %r' % (wFormatTag,))
+        if not self._nchannels:
+            raise Error('bad # of channels')
         self._framesize = self._nchannels * self._sampwidth
         self._comptype = 'NONE'
         self._compname = 'not compressed'