properly handle file closing in error cases (closes #22266)

Lib/tarfile.py

@@ -417,6 +417,7 @@ class _Stream:
         self.pos      = 0L
         self.closed   = False
 
+        try:
             if comptype == "gz":
                 try:
                     import zlib
@@ -429,7 +430,7 @@ class _Stream:
                 else:
                     self._init_write_gz()
 
-        if comptype == "bz2":
+            elif comptype == "bz2":
                 try:
                     import bz2
                 except ImportError:
@@ -439,6 +440,11 @@ class _Stream:
                     self.cmp = bz2.BZ2Decompressor()
                 else:
                     self.cmp = bz2.BZ2Compressor()
+        except:
+            if not self._extfileobj:
+                self.fileobj.close()
+            self.closed = True
+            raise
 
     def __del__(self):
         if hasattr(self, "closed") and not self.closed:
@@ -1685,9 +1691,12 @@ class TarFile(object):
             if filemode not in ("r", "w"):
                 raise ValueError("mode must be 'r' or 'w'")
 
-            t = cls(name, filemode,
-                    _Stream(name, filemode, comptype, fileobj, bufsize),
-                    **kwargs)
+            stream = _Stream(name, filemode, comptype, fileobj, bufsize)
+            try:
+                t = cls(name, filemode, stream, **kwargs)
+            except:
+                stream.close()
+                raise
             t._extfileobj = False
             return t
 
@@ -1718,17 +1727,23 @@ class TarFile(object):
         except (ImportError, AttributeError):
             raise CompressionError("gzip module is not available")
 
-        if fileobj is None:
-            fileobj = bltn_open(name, mode + "b")
+        try:
+            fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj)
+        except OSError:
+            if fileobj is not None and mode == 'r':
+                raise ReadError("not a gzip file")
+            raise
 
         try:
-            t = cls.taropen(name, mode,
-                gzip.GzipFile(name, mode, compresslevel, fileobj),
-                **kwargs)
+            t = cls.taropen(name, mode, fileobj, **kwargs)
         except IOError:
+            fileobj.close()
             if mode == 'r':
                 raise ReadError("not a gzip file")
             raise
+        except:
+            fileobj.close()
+            raise
         t._extfileobj = False
         return t
 
@@ -1753,9 +1768,13 @@ class TarFile(object):
         try:
             t = cls.taropen(name, mode, fileobj, **kwargs)
         except (IOError, EOFError):
+            fileobj.close()
             if mode == 'r':
                 raise ReadError("not a bzip2 file")
             raise
+        except:
+            fileobj.close()
+            raise
         t._extfileobj = False
         return t