…push

After CL 534215 was merged to fix a CVE it introduced
an underflow when we try to decrement sc.curHandlers
in handlerDone.

The func startPush calls runHandler without incrementing
curHandlers. Seems to only affect users of http.Pusher.

For golang/go#63511
For golang/go#63740

Change-Id: Ic537c27c9945c2c2d4306ddb04e9527b65cee320
GitHub-Last-Rev: 249fe55
GitHub-Pull-Request: #197
Reviewed-on: https://go-review.googlesource.com/c/net/+/535595
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Mauri de Souza Meneguzzo <mauri870@gmail.com>
(cherry picked from commit 37479d6)
Reviewed-on: https://go-review.googlesource.com/c/net/+/537956
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

…/http2

After CL 534295 was merged to fix a CVE it introduced
an underflow when we try to decrement sc.curHandlers
in handlerDone.

Pull in a fix from x/net/http2:
http2: fix underflow in http2 server push
https://go-review.googlesource.com/c/net/+/535595

For #63511
Fixes #63740

Change-Id: I5c678ce7dcc53635f3ad5e4999857cb120dfc1ab
GitHub-Last-Rev: 587ffa3
GitHub-Pull-Request: #63561
Reviewed-on: https://go-review.googlesource.com/c/go/+/535575
Run-TryBot: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
(cherry picked from commit 0046c14)
Reviewed-on: https://go-review.googlesource.com/c/go/+/538095
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>