fix: ?uri= url-decode and preserve query

This makes ?uri= param able to process URIs passed by web browsers
https://developer.mozilla.org/en-US/docs/Web/API/Navigator/registerProtocolHandler

core/corehttp/gateway_handler.go

@@ -181,10 +181,17 @@ func (i *gatewayHandler) getOrHeadHandler(w http.ResponseWriter, r *http.Request
 	}
 	originalUrlPath := prefix + requestURI.Path
 
-	// Query parameter handling to support requests produced by navigator.registerProtocolHandler.
-	// E.g. This code will redirect calls to /ipfs/?uri=ipfs%3A%2F%2Fcontent-identifier
-	// to /ipfs/content-identifier.
-	if uri := r.URL.Query().Get("uri"); uri != "" {
+	// ?uri query param support for requests produced by web browsers
+	// via navigator.registerProtocolHandler Web API
+	// https://developer.mozilla.org/en-US/docs/Web/API/Navigator/registerProtocolHandler
+	// TLDR: redirect /ipfs/?uri=ipfs%3A%2F%2Fcid%3Fquery%3Dval to /ipfs/cid?query=val
+	if uriParam := r.URL.Query().Get("uri"); uriParam != "" {
+		// Browsers will pass URI in URL-escaped form, we need to unescape it first
+		uri, err := url.QueryUnescape(uriParam)
+		if err != nil {
+			webError(w, "failed to unescape uri query parameter", err, http.StatusBadRequest)
+			return
+		}
 		u, err := url.Parse(uri)
 		if err != nil {
 			webError(w, "failed to parse uri query parameter", err, http.StatusBadRequest)
@@ -194,7 +201,11 @@ func (i *gatewayHandler) getOrHeadHandler(w http.ResponseWriter, r *http.Request
 			webError(w, "uri query parameter scheme must be ipfs or ipns", err, http.StatusBadRequest)
 			return
 		}
-		http.Redirect(w, r, gopath.Join("/", prefix, u.Scheme, u.Host), http.StatusMovedPermanently)
+		path := u.Path
+		if u.RawQuery != "" { // preserve query if present
+			path = path + "?" + u.RawQuery
+		}
+		http.Redirect(w, r, gopath.Join("/", prefix, u.Scheme, u.Host, path), http.StatusMovedPermanently)
 		return
 	}
 

core/corehttp/gateway_test.go

@@ -170,12 +170,18 @@ func TestUriQueryRedirect(t *testing.T) {
 		status   int
 		location string
 	}{
+		// - Browsers will send original URI in URL-escaped form
+		// - We expect query parameters to be persisted
+		// - We drop fragments, as those should not be sent by a browser
+		{"/ipfs/?uri=ipfs%3A%2F%2FQmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco%2Fwiki%2FFoo_%C4%85%C4%99.html%3Ffilename%3Dtest-%C4%99.html%23header-%C4%85", http.StatusMovedPermanently, "/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Foo_%c4%85%c4%99.html?filename=test-%c4%99.html"},
+		{"/ipfs/?uri=ipns%3A%2F%2Fexample.com%2Fwiki%2FFoo_%C4%85%C4%99.html%3Ffilename%3Dtest-%C4%99.html", http.StatusMovedPermanently, "/ipns/example.com/wiki/Foo_%c4%85%c4%99.html?filename=test-%c4%99.html"},
 		{"/ipfs/?uri=ipfs://" + cid, http.StatusMovedPermanently, "/ipfs/" + cid},
-		{"/ipfs/?uri=ipfs%3A%2F%2F" + cid, http.StatusMovedPermanently, "/ipfs/" + cid},
 		{"/ipfs?uri=ipfs://" + cid, http.StatusMovedPermanently, "/ipfs/?uri=ipfs://" + cid},
 		{"/ipfs/?uri=ipns://" + cid, http.StatusMovedPermanently, "/ipns/" + cid},
+		{"/ipns/?uri=ipfs%3A%2F%2FQmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco%2Fwiki%2FFoo_%C4%85%C4%99.html%3Ffilename%3Dtest-%C4%99.html%23header-%C4%85", http.StatusMovedPermanently, "/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Foo_%c4%85%c4%99.html?filename=test-%c4%99.html"},
+		{"/ipns/?uri=ipns%3A%2F%2Fexample.com%2Fwiki%2FFoo_%C4%85%C4%99.html%3Ffilename%3Dtest-%C4%99.html", http.StatusMovedPermanently, "/ipns/example.com/wiki/Foo_%c4%85%c4%99.html?filename=test-%c4%99.html"},
 		{"/ipns?uri=ipns://" + cid, http.StatusMovedPermanently, "/ipns/?uri=ipns://" + cid},
-		{"/ipns/?uri=ipfs://" + cid, http.StatusMovedPermanently, "/ipfs/" + cid},
+		{"/ipns/?uri=ipns://" + cid, http.StatusMovedPermanently, "/ipns/" + cid},
 		{"/ipns/?uri=ipfs://" + cid, http.StatusMovedPermanently, "/ipfs/" + cid},
 		{"/ipfs/?uri=unsupported://" + cid, http.StatusBadRequest, ""},
 		{"/ipfs/?uri=" + cid, http.StatusBadRequest, ""},