Clean up code to open "Create stream" panel.

This fixes a bug where hitting the "n" hotkey was
causing double work related to the hashchange system.

The code is now organized like this:

    do_open_create_stream() does the GUI piece

    We call the above directly for hash changes.

    For in-app actions, whether clicks or hotkeys,
    we call open_create_stream(), which delegates
    most of the work to do_open_create_stream() but
    also updates the hash.

frontend_tests/node_tests/hotkey.js

@@ -227,7 +227,7 @@ run_test('basic_chars', () => {
     overlays.is_active = return_true;
     assert_mapping('S', 'subs.keyboard_sub');
     assert_mapping('V', 'subs.view_stream');
-    assert_mapping('n', 'subs.new_stream_clicked');
+    assert_mapping('n', 'subs.open_create_stream');
     page_params.can_create_streams = false;
     assert_unmapped('n');
     overlays.streams_open = return_false;

static/js/hotkey.js

@@ -613,7 +613,7 @@ exports.process_hotkey = function (e, hotkey) {
             return true;
         }
         if (event_name === 'n_key' && overlays.streams_open() && page_params.can_create_streams) {
-            subs.new_stream_clicked();
+            subs.open_create_stream();
             return true;
         }
         return false;

static/js/stream_create.js

@@ -234,11 +234,6 @@ exports.new_stream_clicked = function (stream_name) {
     if (window.innerWidth > 700) {
         $('#create_stream_name').focus();
     }
-
-    // change the hash to #streams/new to allow for linking and
-    // easy discovery.
-
-    window.location.hash = "#streams/new";
 };
 
 function clear_error_display() {

static/js/subs.js

@@ -609,7 +609,7 @@ exports.change_state = (function () {
         if (hash.arguments.length > 0) {
             // if in #streams/new form.
             if (hash.arguments[0] === "new") {
-                exports.new_stream_clicked();
+                exports.do_open_create_stream();
             } else if (hash.arguments[0] === "all") {
                 maybe_select_tab("all-streams");
             } else if (hash.arguments[0] === "subscribed") {
@@ -772,7 +772,10 @@ function ajaxUnsubscribe(sub) {
     });
 }
 
-exports.new_stream_clicked = function () {
+exports.do_open_create_stream = function () {
+    // Only call this directly for hash changes.
+    // Prefer open_create_stream().
+
     var stream = $.trim($("#search_stream_name").val());
 
     if (!should_list_all_streams()) {
@@ -785,6 +788,16 @@ exports.new_stream_clicked = function () {
     stream_create.new_stream_clicked(stream);
 };
 
+exports.open_create_stream = function () {
+    exports.do_open_create_stream();
+
+    // this will change the hash which will attempt to retrigger the create
+    // stream code, so we prevent this once.
+    exports.change_state.prevent_once();
+    window.location.hash = "#streams/new";
+};
+
+
 exports.sub_or_unsub = function (sub) {
     if (sub.subscribed) {
         ajaxUnsubscribe(sub);
@@ -806,10 +819,7 @@ exports.initialize = function () {
 
     $("#subscriptions_table").on("click", ".create_stream_button", function (e) {
         e.preventDefault();
-        exports.new_stream_clicked();
+        exports.open_create_stream();
-        // this will change the hash which will attempt to retrigger the create
-        // stream code, so we prevent this once.
-        exports.change_state.prevent_once();
     });
 
     $(".subscriptions").on("click", "[data-dismiss]", function (e) {