Issue #18919: If the close() method of a writer in the sunau or wave module

failed, second invocation of close() and destructor no more raise an
exception.  Second invocation of close() on sunau writer now has no effects.
The aifc module now accepts lower case of names of the 'ulaw' and 'alaw'
codecs.

Lib/aifc.py

@@ -486,7 +486,7 @@ class Aifc_read:
                 try:
                     import cl
                 except ImportError:
-                    if self._comptype == 'ULAW':
+                    if self._comptype in ('ULAW', 'ulaw'):
                         try:
                             import audioop
                             self._convert = self._ulaw2lin
@@ -495,9 +495,9 @@ class Aifc_read:
                         except ImportError:
                             pass
                     raise Error, 'cannot read compressed AIFF-C files'
-                if self._comptype == 'ULAW':
+                if self._comptype in ('ULAW', 'ulaw'):
                     scheme = cl.G711_ULAW
-                elif self._comptype == 'ALAW':
+                elif self._comptype in ('ALAW', 'alaw'):
                     scheme = cl.G711_ALAW
                 else:
                     raise Error, 'unsupported compression type'
@@ -654,7 +654,7 @@ class Aifc_write:
     def setcomptype(self, comptype, compname):
         if self._nframeswritten:
             raise Error, 'cannot change parameters after starting to write'
-        if comptype not in ('NONE', 'ULAW', 'ALAW', 'G722'):
+        if comptype not in ('NONE', 'ULAW', 'ulaw', 'ALAW', 'alaw', 'G722'):
             raise Error, 'unsupported compression type'
         self._comptype = comptype
         self._compname = compname
@@ -674,7 +674,7 @@ class Aifc_write:
         nchannels, sampwidth, framerate, nframes, comptype, compname = info
         if self._nframeswritten:
             raise Error, 'cannot change parameters after starting to write'
-        if comptype not in ('NONE', 'ULAW', 'ALAW', 'G722'):
+        if comptype not in ('NONE', 'ULAW', 'ulaw', 'ALAW', 'alaw', 'G722'):
             raise Error, 'unsupported compression type'
         self.setnchannels(nchannels)
         self.setsampwidth(sampwidth)
@@ -803,7 +803,7 @@ class Aifc_write:
         try:
             import cl
         except ImportError:
-            if self._comptype == 'ULAW':
+            if self._comptype in ('ULAW', 'ulaw'):
                 try:
                     import audioop
                     self._convert = self._lin2ulaw
@@ -811,9 +811,9 @@ class Aifc_write:
                 except ImportError:
                     pass
             raise Error, 'cannot write compressed AIFF-C files'
-        if self._comptype == 'ULAW':
+        if self._comptype in ('ULAW', 'ulaw'):
             scheme = cl.G711_ULAW
-        elif self._comptype == 'ALAW':
+        elif self._comptype in ('ALAW', 'alaw'):
             scheme = cl.G711_ALAW
         else:
             raise Error, 'unsupported compression type'
@@ -866,7 +866,7 @@ class Aifc_write:
         _write_short(self._file, self._nchannels)
         self._nframes_pos = self._file.tell()
         _write_ulong(self._file, self._nframes)
-        if self._comptype in ('ULAW', 'ALAW', 'G722'):
+        if self._comptype in ('ULAW', 'ulaw', 'ALAW', 'alaw', 'G722'):
             _write_short(self._file, 8)
         else:
             _write_short(self._file, self._sampwidth * 8)

Lib/sunau.py

@@ -406,12 +406,15 @@ class Au_write:
             self._patchheader()
 
     def close(self):
-        self._ensure_header_written()
-        if self._nframeswritten != self._nframes or \
-                  self._datalength != self._datawritten:
-            self._patchheader()
-        self._file.flush()
-        self._file = None
+        if self._file:
+            try:
+                self._ensure_header_written()
+                if self._nframeswritten != self._nframes or \
+                        self._datalength != self._datawritten:
+                    self._patchheader()
+                self._file.flush()
+            finally:
+                self._file = None
 
     #
     # private methods

Lib/wave.py

@@ -436,11 +436,13 @@ class Wave_write:
 
     def close(self):
         if self._file:
-            self._ensure_header_written(0)
-            if self._datalength != self._datawritten:
-                self._patchheader()
-            self._file.flush()
-            self._file = None
+            try:
+                self._ensure_header_written(0)
+                if self._datalength != self._datawritten:
+                    self._patchheader()
+                self._file.flush()
+            finally:
+                self._file = None
         if self._i_opened_the_file:
             self._i_opened_the_file.close()
             self._i_opened_the_file = None

Misc/NEWS

@@ -32,6 +32,12 @@ Core and Builtins
 Library
 -------
 
+- Issue #18919: If the close() method of a writer in the sunau or wave module
+  failed, second invocation of close() and destructor no more raise an
+  exception.  Second invocation of close() on sunau writer now has no effects.
+  The aifc module now accepts lower case of names of the 'ulaw' and 'alaw'
+  codecs.
+
 - Issue #19131: The aifc module now correctly reads and writes sampwidth of
   compressed streams.