post tooltips: don't show if lost focus during ajax call (#3689).

Fix the tooltip appearing and getting stuck when the user mouses out
during the ajax request.

app/assets/javascripts/post_tooltips.js.erb

@@ -6,6 +6,12 @@ Danbooru.PostTooltip.render_tooltip = function (event, qtip) {
   $.get("/posts/" + post_id, { variant: "tooltip" }).then(function (html) {
     qtip.set("content.text", html);
     qtip.elements.tooltip.removeClass("post-tooltip-loading");
+
+    // Hide the tooltip if the user stopped hovering before the ajax request completed.
+    if (Danbooru.PostTooltip.lostFocus) {
+      console.log("hiding");
+      qtip.hide();
+    }
   });
 };
 
@@ -61,6 +67,12 @@ Danbooru.PostTooltip.initialize = function () {
     } else {
       $(this).qtip(Danbooru.PostTooltip.QTIP_OPTIONS, event);
     }
+
+    Danbooru.PostTooltip.lostFocus = false;
+  });
+
+  $(document).on("mouseleave", Danbooru.PostTooltip.POST_SELECTOR, function (event) {
+    Danbooru.PostTooltip.lostFocus = true;
   });
 
   // Hide tooltips when pressing keys or clicking thumbnails.