Issue #10266: uu.decode didn't close in_file explicitly when it was given

as a filename.  Patch by Brian Brazil.

Lib/test/test_uu.py

@@ -196,6 +196,23 @@ class UUFileTest(unittest.TestCase):
         finally:
             self._kill(f)
 
+    def test_decode_filename(self):
+        f = None
+        try:
+            support.unlink(self.tmpin)
+            f = open(self.tmpin, 'wb')
+            f.write(encodedtextwrapped(0o644, self.tmpout))
+            f.close()
+
+            uu.decode(self.tmpin)
+
+            f = open(self.tmpout, 'rb')
+            s = f.read()
+            f.close()
+            self.assertEqual(s, plaintext)
+        finally:
+            self._kill(f)
+
     def test_decodetwice(self):
         # Verify that decode() will refuse to overwrite an existing file
         f = None

Lib/uu.py

@@ -92,66 +92,70 @@ def decode(in_file, out_file=None, mode=None, quiet=False):
     #
     # Open the input file, if needed.
     #
+    opened_files = []
     if in_file == '-':
         in_file = sys.stdin.buffer
     elif isinstance(in_file, str):
         in_file = open(in_file, 'rb')
-    #
-    # Read until a begin is encountered or we've exhausted the file
-    #
-    while True:
-        hdr = in_file.readline()
-        if not hdr:
-            raise Error('No valid begin line found in input file')
-        if not hdr.startswith(b'begin'):
-            continue
-        hdrfields = hdr.split(b' ', 2)
-        if len(hdrfields) == 3 and hdrfields[0] == b'begin':
+        opened_files.append(in_file)
+
+    try:
+        #
+        # Read until a begin is encountered or we've exhausted the file
+        #
+        while True:
+            hdr = in_file.readline()
+            if not hdr:
+                raise Error('No valid begin line found in input file')
+            if not hdr.startswith(b'begin'):
+                continue
+            hdrfields = hdr.split(b' ', 2)
+            if len(hdrfields) == 3 and hdrfields[0] == b'begin':
+                try:
+                    int(hdrfields[1], 8)
+                    break
+                except ValueError:
+                    pass
+        if out_file is None:
+            # If the filename isn't ASCII, what's up with that?!?
+            out_file = hdrfields[2].rstrip(b' \t\r\n\f').decode("ascii")
+            if os.path.exists(out_file):
+                raise Error('Cannot overwrite existing file: %s' % out_file)
+        if mode is None:
+            mode = int(hdrfields[1], 8)
+        #
+        # Open the output file
+        #
+        if out_file == '-':
+            out_file = sys.stdout.buffer
+        elif isinstance(out_file, str):
+            fp = open(out_file, 'wb')
             try:
-                int(hdrfields[1], 8)
-                break
-            except ValueError:
+                os.path.chmod(out_file, mode)
+            except AttributeError:
                 pass
-    if out_file is None:
-        # If the filename isn't ASCII, what's up with that?!?
-        out_file = hdrfields[2].rstrip(b' \t\r\n\f').decode("ascii")
-        if os.path.exists(out_file):
-            raise Error('Cannot overwrite existing file: %s' % out_file)
-    if mode is None:
-        mode = int(hdrfields[1], 8)
-    #
-    # Open the output file
-    #
-    opened = False
-    if out_file == '-':
-        out_file = sys.stdout.buffer
-    elif isinstance(out_file, str):
-        fp = open(out_file, 'wb')
-        try:
-            os.path.chmod(out_file, mode)
-        except AttributeError:
-            pass
-        out_file = fp
-        opened = True
-    #
-    # Main decoding loop
-    #
-    s = in_file.readline()
-    while s and s.strip(b' \t\r\n\f') != b'end':
-        try:
-            data = binascii.a2b_uu(s)
-        except binascii.Error as v:
-            # Workaround for broken uuencoders by /Fredrik Lundh
-            nbytes = (((s[0]-32) & 63) * 4 + 5) // 3
-            data = binascii.a2b_uu(s[:nbytes])
-            if not quiet:
-                sys.stderr.write("Warning: %s\n" % v)
-        out_file.write(data)
+            out_file = fp
+            opened_files.append(out_file)
+        #
+        # Main decoding loop
+        #
         s = in_file.readline()
-    if not s:
-        raise Error('Truncated input file')
-    if opened:
-        out_file.close()
+        while s and s.strip(b' \t\r\n\f') != b'end':
+            try:
+                data = binascii.a2b_uu(s)
+            except binascii.Error as v:
+                # Workaround for broken uuencoders by /Fredrik Lundh
+                nbytes = (((s[0]-32) & 63) * 4 + 5) // 3
+                data = binascii.a2b_uu(s[:nbytes])
+                if not quiet:
+                    sys.stderr.write("Warning: %s\n" % v)
+            out_file.write(data)
+            s = in_file.readline()
+        if not s:
+            raise Error('Truncated input file')
+    finally:
+        for f in opened_files:
+            f.close()
 
 def test():
     """uuencode/uudecode main program"""

Misc/NEWS

@@ -59,6 +59,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #10266: uu.decode didn't close in_file explicitly when it was given
+  as a filename.  Patch by Brian Brazil.
+
 - Issue #10160: Speed up operator.attrgetter.  Patch by Christos Georgiou.
 
 - logging: Added style option to basicConfig() to allow %, {} or $-formatting.