net/http: allow multiple spaces between method and path in mux patterns

Fixes #64910

Change-Id: I14fd1e35c95b14591e3ad7b889dc1ab19a008730
GitHub-Last-Rev: b8d436cdee93d103703e7e6d4bb28315c5035300
GitHub-Pull-Request: golang/go#65868
Reviewed-on: https://go-review.googlesource.com/c/go/+/565916
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>

diff --git a/doc/next/6-stdlib/99-minor/net/http/64910.md b/doc/next/6-stdlib/99-minor/net/http/64910.md
new file mode 100644 (file)
index 0000000..020e18b
--- /dev/null
+++ b/doc/next/6-stdlib/99-minor/net/http/64910.md
@@ -0,0 +1,2 @@
+The patterns used by [`net/http.ServeMux`](//net/http#ServeMux) allow
+multiple spaces matching regexp '[ \t]+'.

diff --git a/src/net/http/pattern.go b/src/net/http/pattern.go
index f6af19b0f4437f0011e50a69ac91eaf636d53257..8fd120e7775c1c6f209db84322a4b1112745f57d 100644 (file)
--- a/src/net/http/pattern.go
+++ b/src/net/http/pattern.go
@@ -76,7 +76,7 @@ type segment struct {
 //     a literal or a wildcard of the form "{name}", "{name...}", or "{$}".
 //
 // METHOD, HOST and PATH are all optional; that is, the string can be "/".
-// If METHOD is present, it must be followed by a single space.
+// If METHOD is present, it must be followed by at least one space or tab.
 // Wildcard names must be valid Go identifiers.
 // The "{$}" and "{name...}" wildcard must occur at the end of PATH.
 // PATH may end with a '/'.
@@ -92,7 +92,10 @@ func parsePattern(s string) (_ *pattern, err error) {
                }
        }()
 
-       method, rest, found := strings.Cut(s, " ")
+       method, rest, found := s, "", false
+       if i := strings.IndexAny(s, " \t"); i >= 0 {
+               method, rest, found = s[:i], strings.TrimLeft(s[i+1:], " \t"), true
+       }
        if !found {
                rest = method
                method = ""

diff --git a/src/net/http/pattern_test.go b/src/net/http/pattern_test.go
index f0c84d243ec96c547918de7c1faa312728e2292d..833fe88bf6ab9833c7063456fe50bc0f33b7cfd3 100644 (file)
--- a/src/net/http/pattern_test.go
+++ b/src/net/http/pattern_test.go
@@ -98,6 +98,23 @@ func TestParsePattern(t *testing.T) {
                        "/%61%62/%7b/%",
                        pattern{segments: []segment{lit("ab"), lit("{"), lit("%")}},
                },
+               // Allow multiple spaces matching regexp '[ \t]+' between method and path.
+               {
+                       "GET\t  /",
+                       pattern{method: "GET", segments: []segment{multi("")}},
+               },
+               {
+                       "POST \t  example.com/foo/{w}",
+                       pattern{
+                               method:   "POST",
+                               host:     "example.com",
+                               segments: []segment{lit("foo"), wild("w")},
+                       },
+               },
+               {
+                       "DELETE    \texample.com/a/{foo12}/{$}",
+                       pattern{method: "DELETE", host: "example.com", segments: []segment{lit("a"), wild("foo12"), lit("/")}},
+               },
        } {
                got := mustParsePattern(t, test.in)
                if !got.equal(&test.want) {

diff --git a/src/net/http/server.go b/src/net/http/server.go
index 0ba88d1119e4f97aa9cbe6dff3ee6640388887e2..7d73cca43fd21f0dbb4955f06aeabbcfc596f8c1 100644 (file)
--- a/src/net/http/server.go
+++ b/src/net/http/server.go
@@ -2335,7 +2335,7 @@ func RedirectHandler(url string, code int) Handler {
 //     [METHOD ][HOST]/[PATH]
 //
 // All three parts are optional; "/" is a valid pattern.
-// If METHOD is present, it must be followed by a single space.
+// If METHOD is present, it must be followed by at least one space or tab.
 //
 // Literal (that is, non-wildcard) parts of a pattern match
 // the corresponding parts of a request case-sensitively.