tree 6d0c7094132222f814a82138768850f00eb85ab2
parent a2adbc876e9362f064afffcb51ce677e2f988c5e
author Cherry Zhang <cherryyz@google.com> 1605658251 -0500
committer Carlos Amedee <carlos@golang.org> 1607004372 +0000

[release-branch.go1.15] cmd/link: recompute heapPos after copyHeap

Immediately after a forward Seek, the offset we're writing to is
beyond len(buf)+len(heap):

|<--- buf --->|<--- heap --->|
                                    ^
                                    off

If we do a copyHeap at this point, the new heapPos should not be
0:

|<---------- buf ----------->|<-heap->|
                                    ^
                                    off

Recompute it.

Updates #42082
Fixes #42948

Change-Id: Icb3e4e1c7bf7d1fd3d76a2e0d7dfcb319c661534
Reviewed-on: https://go-review.googlesource.com/c/go/+/270942
Run-TryBot: Carlos Amedee <carlos@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Trust: Cherry Zhang <cherryyz@google.com>