Issue #23865: close() methods in multiple modules now are idempotent and more
robust at shutdown. If needs to release multiple resources, they are released
even if errors are occured.
diff --git a/Lib/gzip.py b/Lib/gzip.py
index 8b12225..7ad00e1 100644
--- a/Lib/gzip.py
+++ b/Lib/gzip.py
@@ -500,19 +500,21 @@
         return self.fileobj is None
 
     def close(self):
-        if self.fileobj is None:
+        fileobj = self.fileobj
+        if fileobj is None:
             return
-        if self.mode == WRITE:
-            self.fileobj.write(self.compress.flush())
-            write32u(self.fileobj, self.crc)
-            # self.size may exceed 2GB, or even 4GB
-            write32u(self.fileobj, self.size & 0xffffffff)
-            self.fileobj = None
-        elif self.mode == READ:
-            self.fileobj = None
-        if self.myfileobj:
-            self.myfileobj.close()
-            self.myfileobj = None
+        self.fileobj = None
+        try:
+            if self.mode == WRITE:
+                fileobj.write(self.compress.flush())
+                write32u(fileobj, self.crc)
+                # self.size may exceed 2GB, or even 4GB
+                write32u(fileobj, self.size & 0xffffffff)
+        finally:
+            myfileobj = self.myfileobj
+            if myfileobj:
+                self.myfileobj = None
+                myfileobj.close()
 
     def flush(self,zlib_mode=zlib.Z_SYNC_FLUSH):
         self._check_closed()