From 0ab2693da665479f8430a890b828617754b698e4 Mon Sep 17 00:00:00 2001
From: Xiaoxing Ye <ye@xiaoxing.us>
Date: Wed, 22 Jan 2020 00:34:29 +0800
Subject: [PATCH] doc: add desc about gzip and http dump

Fix #3872
---
 docs/content/docs.md | 9 ++++++++-
 fs/fshttp/http.go    | 7 +++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/docs/content/docs.md b/docs/content/docs.md
index 75f11c200..78aba9956 100644
--- a/docs/content/docs.md
+++ b/docs/content/docs.md
@@ -1378,7 +1378,14 @@ Write CPU profile to file.  This can be analysed with `go tool pprof`.
 #### --dump flag,flag,flag ####
 
 The `--dump` flag takes a comma separated list of flags to dump info
-about.  These are:
+about.
+
+Note that some headers including `Accept-Encoding` as shown may not 
+be correct in the request and the response may not show `Content-Encoding`
+if the go standard libraries auto gzip encoding was in effect. In this case 
+the body of the request will be gunzipped before showing it.
+
+The available flags are:
 
 #### --dump headers ####
 
diff --git a/fs/fshttp/http.go b/fs/fshttp/http.go
index 1414426be..8caef8a4f 100644
--- a/fs/fshttp/http.go
+++ b/fs/fshttp/http.go
@@ -180,6 +180,13 @@ func NewTransportCustom(ci *fs.ConfigInfo, customize func(*http.Transport)) http
 	t.IdleConnTimeout = 60 * time.Second
 	t.ExpectContinueTimeout = ci.ExpectContinueTimeout
 
+	if ci.Dump&(fs.DumpHeaders|fs.DumpBodies|fs.DumpAuth|fs.DumpRequests|fs.DumpResponses) != 0 {
+		fs.Debugf(nil, "You have specified to dump information. Please be noted that the "+
+			"Accept-Encoding as shown may not be correct in the request and the response may not show "+
+			"Content-Encoding if the go standard libraries auto gzip encoding was in effect. In this case"+
+			" the body of the request will be gunzipped before showing it.")
+	}
+
 	// customize the transport if required
 	if customize != nil {
 		customize(t)