diff --git a/mercurial/bundle2.py b/mercurial/bundle2.py
--- a/mercurial/bundle2.py
+++ b/mercurial/bundle2.py
@@ -363,7 +363,7 @@
                 self.count = count
                 self.current = p
                 yield p
-                p.seek(0, os.SEEK_END)
+                p.consume()
                 self.current = None
         self.iterator = func()
         return self.iterator
@@ -385,11 +385,11 @@
             try:
                 if self.current:
                     # consume the part content to not corrupt the stream.
-                    self.current.seek(0, os.SEEK_END)
+                    self.current.consume()
 
                 for part in self.iterator:
                     # consume the bundle content
-                    part.seek(0, os.SEEK_END)
+                    part.consume()
             except Exception:
                 seekerror = True
 
@@ -856,10 +856,11 @@
         while headerblock is not None:
             part = seekableunbundlepart(self.ui, headerblock, self._fp)
             yield part
-            # Seek to the end of the part to force it's consumption so the next
-            # part can be read. But then seek back to the beginning so the
-            # code consuming this generator has a part that starts at 0.
-            part.seek(0, os.SEEK_END)
+            # Ensure part is fully consumed so we can start reading the next
+            # part.
+            part.consume()
+            # But then seek back to the beginning so the code consuming this
+            # generator has a part that starts at 0.
             part.seek(0, os.SEEK_SET)
             headerblock = self._readpartheader()
         indebug(self.ui, 'end of bundle2 stream')
@@ -1165,7 +1166,7 @@
             raise
         finally:
             if not hardabort:
-                part.seek(0, os.SEEK_END)
+                part.consume()
         self.ui.debug('bundle2-input-stream-interrupt:'
                       ' closing out of band context\n')
 
@@ -1300,6 +1301,20 @@
         """Generator of decoded chunks in the payload."""
         return decodepayloadchunks(self.ui, self._fp)
 
+    def consume(self):
+        """Read the part payload until completion.
+
+        By consuming the part data, the underlying stream read offset will
+        be advanced to the next part (or end of stream).
+        """
+        if self.consumed:
+            return
+
+        chunk = self.read(32768)
+        while chunk:
+            self._pos += len(chunk)
+            chunk = self.read(32768)
+
     def read(self, size=None):
         """read payload data"""
         if not self._initialized: