Use forked version of gziphandler (#17852)

vendor/github.com/NYTimes/gziphandler/.travis.yml

@@ -1,10 +0,0 @@
-language: go
-go:
-  - 1.x
-  - tip
-env:
-  - GO111MODULE=on
-install:
-  - go mod download
-script:
-  - go test -race -v

vendor/github.com/NYTimes/gziphandler/go.mod

@@ -1,8 +0,0 @@
-module github.com/NYTimes/gziphandler
-
-go 1.11
-
-require (
-	github.com/klauspost/compress v1.10.11
-	github.com/stretchr/testify v1.3.0
-)

vendor/github.com/mattermost/gziphandler/.golangci.yml

@@ -0,0 +1,48 @@
+run:
+  timeout: 5m
+  modules-download-mode: readonly
+
+linters-settings:
+  gofmt:
+    simplify: true
+  govet:
+    check-shadowing: true
+    disable-all: true
+    enable:
+      - asmdecl      # report mismatches between assembly files and Go declarations
+      - assign       # check for useless assignments
+      - atomic       # check for common mistakes using the sync/atomic package
+      - bools        # check for common mistakes involving boolean operators
+      - buildtag     # check that +build tags are well-formed and correctly located
+      - cgocall      # detect some violations of the cgo pointer passing rules
+      - composites   # check for unkeyed composite literals
+      - copylocks    # check for locks erroneously passed by value
+      - errorsas     # report passing non-pointer or non-error values to errors.As
+      - httpresponse # check for mistakes using HTTP responses
+      - loopclosure  # check references to loop variables from within nested functions
+      - lostcancel   # check cancel func returned by context.WithCancel is called
+      - nilfunc      # check for useless comparisons between functions and nil
+      - printf       # check consistency of Printf format strings and arguments
+      - shift        # check for shifts that equal or exceed the width of the integer
+      - stdmethods   # check signature of methods of well-known interfaces
+      - structtag    # check that struct field tags conform to reflect.StructTag.Get
+      - tests        # check for common mistaken usages of tests and examples
+      - unmarshal    # report passing non-pointer or non-interface values to unmarshal
+      - unreachable  # check for unreachable code
+      - unsafeptr    # check for invalid conversions of uintptr to unsafe.Pointer
+      - unusedresult # check for unused results of calls to some functions
+
+linters:
+  disable-all: true
+  enable:
+    - deadcode
+    - gofmt
+    - gosimple
+    - govet
+    - ineffassign
+    - scopelint
+    - structcheck
+    - staticcheck
+    - unconvert
+    - unused
+    - varcheck

vendor/github.com/mattermost/gziphandler/Makefile

@@ -0,0 +1,23 @@
+.PHONY: build check-style install run test verify-gomod
+
+# Variables
+GO=go
+
+# Test runs go test command
+test:
+	$(GO) test -cover -race ./...
+
+# Checks code style by running golangci-lint on codebase.
+check-style:
+	@if ! [ -x "$$(command -v golangci-lint)" ]; then \
+		echo "golangci-lint is not installed. Please see https://github.com/golangci/golangci-lint#install for installation instructions."; \
+		exit 1; \
+	fi; \
+
+	@echo Running golangci-lint
+	golangci-lint run ./...
+
+# Check modules
+verify-gomod:
+	$(GO) mod download
+	$(GO) mod verify

vendor/github.com/mattermost/gziphandler/README.md

@@ -6,9 +6,12 @@ response body, for clients which support it. Although it's usually simpler to
 leave that to a reverse proxy (like nginx or Varnish), this package is useful
 when that's undesirable.
 
+**This is forked from the original repo at https://github.com/nytimes/gziphandler
+with this [PR](https://github.com/nytimes/gziphandler/pull/107) included.**
+
 ## Install
 ```bash
-go get -u github.com/NYTimes/gziphandler
+go get -u github.com/mattermost/gziphandler
 ```
 
 ## Usage
@@ -23,7 +26,7 @@ package main
 import (
 	"io"
 	"net/http"
-	"github.com/NYTimes/gziphandler"
+	"github.com/mattermost/gziphandler"
 )
 
 func main() {
@@ -52,5 +55,5 @@ The docs can be found at [godoc.org][docs], as usual.
 
 
 
-[docs]:     https://godoc.org/github.com/NYTimes/gziphandler
-[license]:  https://github.com/NYTimes/gziphandler/blob/master/LICENSE
+[docs]:     https://godoc.org/github.com/mattermost/gziphandler
+[license]:  https://github.com/mattermost/gziphandler/blob/master/LICENSE

vendor/github.com/mattermost/gziphandler/go.mod

@@ -0,0 +1,8 @@
+module github.com/mattermost/gziphandler
+
+go 1.11
+
+require (
+	github.com/klauspost/compress v1.13.1
+	github.com/stretchr/testify v1.3.0
+)

vendor/github.com/mattermost/gziphandler/go.sum

@@ -1,7 +1,8 @@
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/klauspost/compress v1.10.11 h1:K9z59aO18Aywg2b/WSgBaUX99mHy2BES18Cr5lBKZHk=
-github.com/klauspost/compress v1.10.11/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
+github.com/golang/snappy v0.0.3/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
+github.com/klauspost/compress v1.13.1 h1:wXr2uRxZTJXHLly6qhJabee5JqIhTRoLBhDOA74hDEQ=
+github.com/klauspost/compress v1.13.1/go.mod h1:8dP1Hq4DHOhN9w426knH3Rhby4rFm6D8eO+e+Dq5Gzg=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

vendor/github.com/mattermost/gziphandler/gzip.go

@@ -1,4 +1,4 @@
-package gziphandler // import "github.com/NYTimes/gziphandler"
+package gziphandler // import "github.com/mattermost/gziphandler"
 
 import (
 	"bufio"
@@ -94,7 +94,7 @@ type GzipResponseWriterWithCloseNotify struct {
 }
 
 func (w GzipResponseWriterWithCloseNotify) CloseNotify() <-chan bool {
-	return w.ResponseWriter.(http.CloseNotifier).CloseNotify()
+	return w.ResponseWriter.(http.CloseNotifier).CloseNotify() //nolint:staticcheck
 }
 
 // Write appends data to the gzip writer.
@@ -332,7 +332,7 @@ func GzipHandlerWithOpts(opts ...option) (func(http.Handler) http.Handler, error
 				}
 				defer gw.Close()
 
-				if _, ok := w.(http.CloseNotifier); ok {
+				if _, ok := w.(http.CloseNotifier); ok { //nolint:staticcheck
 					gwcn := GzipResponseWriterWithCloseNotify{gw}
 					h.ServeHTTP(gwcn, r)
 				} else {