net/http: note that "HTTP/2" is invalid for ParseHTTPVersion

Change-Id: Ieba05dea892ec9855a63b80e456bcf9188eef855
GitHub-Last-Rev: 5f7663ac4aaecb01a27a04309277240fd15759c9
GitHub-Pull-Request: golang/go#41806
Reviewed-on: https://go-review.googlesource.com/c/go/+/259758
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Trust: Damien Neil <dneil@google.com>

diff --git a/src/net/http/request.go b/src/net/http/request.go
index 5251ebea665e8828a0ba886bf8aa6564c00482b9..aca55b1ca7b65c6af0c5e049dce5c0fd5e0c0155 100644 (file)
--- a/src/net/http/request.go
+++ b/src/net/http/request.go
@@ -779,7 +779,8 @@ func removeZone(host string) string {
 }
 
 // ParseHTTPVersion parses an HTTP version string.
-// "HTTP/1.0" returns (1, 0, true).
+// "HTTP/1.0" returns (1, 0, true). Note that strings without
+// a minor version, such as "HTTP/2", are not valid.
 func ParseHTTPVersion(vers string) (major, minor int, ok bool) {
        const Big = 1000000 // arbitrary upper bound
        switch vers {