Introduce new Replacer fields {rewrite_path}, {rewrite_path_escaped}; issue #1185 (#1364)

* Fix #1185

* Return normal path if no rewrite has happened

* Revert change, not required

* Updated tests

caddyhttp/httpserver/replacer.go

@@ -223,8 +223,22 @@ func (r *replacer) getSubstitution(key string) string {
 		}
 		return host
 	case "{path}":
-		return r.request.URL.Path
+		// if a rewrite has happened, the original URI should be used as the path
+		// rather than the rewritten URI
+		path := r.request.Header.Get("Caddy-Rewrite-Original-URI")
+		if path == "" {
+			path = r.request.URL.Path
+		}
+		return path
 	case "{path_escaped}":
+		path := r.request.Header.Get("Caddy-Rewrite-Original-URI")
+		if path == "" {
+			path = r.request.URL.Path
+		}
+		return url.QueryEscape(path)
+	case "{rewrite_path}":
+		return r.request.URL.Path
+	case "{rewrite_path_escaped}":
 		return url.QueryEscape(r.request.URL.Path)
 	case "{query}":
 		return r.request.URL.RawQuery

caddyhttp/rewrite/rewrite_test.go

@@ -24,7 +24,8 @@ func TestRewrite(t *testing.T) {
 	regexps := [][]string{
 		{"/reg/", ".*", "/to", ""},
 		{"/r/", "[a-z]+", "/toaz", "!.html|"},
-		{"/url/", "a([a-z0-9]*)s([A-Z]{2})", "/to/{path}", ""},
+		{"/path/", "[a-z0-9]", "/to/{path}", ""},
+		{"/url/", "a([a-z0-9]*)s([A-Z]{2})", "/to/{rewrite_path}", ""},
 		{"/ab/", "ab", "/ab?{query}", ".txt|"},
 		{"/ab/", "ab", "/ab?type=html&{query}", ".html|"},
 		{"/abc/", "ab", "/abc/{file}", ".html|"},
@@ -71,6 +72,8 @@ func TestRewrite(t *testing.T) {
 		{"/r/z", "/toaz"},
 		{"/r/z.html", "/r/z.html"},
 		{"/r/z.js", "/toaz"},
+		{"/path/a1b2c", "/to/path/a1b2c"},
+		{"/path/d3e4f", "/to/path/d3e4f"},
 		{"/url/asAB", "/to/url/asAB"},
 		{"/url/aBsAB", "/url/aBsAB"},
 		{"/url/a00sAB", "/to/url/a00sAB"},

caddyhttp/rewrite/to_test.go

@@ -23,6 +23,7 @@ func TestTo(t *testing.T) {
 		{"/?a=b", "/testdir /index.php?{query}", "/index.php?a=b"},
 		{"/?a=b", "/testdir/ /index.php?{query}", "/testdir/?a=b"},
 		{"/test?url=http://", " /p/{path}?{query}", "/p/test?url=http://"},
+		{"/test?url=http://", " /p/{rewrite_path}?{query}", "/p/test?url=http://"},
 		{"/test/?url=http://", " /{uri}", "/test/?url=http://"},
 	}