non public plugins were disabling addition of public plugins

CHANGELOG

 minerva (12.2.0~beta.2) unstable; urgency=medium
+  * Bug fix: plugin can be added after plugin has been removed in admin plugin 
+    panel (#686)
   * Bug fix: too many annotations (>=100) caused misaligning in the left panel 
     (#708)
   * Bug fix: text was outside the popup window (#711)

frontend-js/src/main/js/gui/admin/AddPluginDialog.js

@@ -176,7 +176,7 @@ AddPluginDialog.prototype.onValidateClicked = function () {
   }).then(function (plugins) {
     for (var i = 0; i < plugins.length; i++) {
       var pluginData = plugins[i];
-      if (pluginData.getUrls().indexOf(url) >= 0) {
+      if (pluginData.getUrls().indexOf(url) >= 0 && pluginData.isPublic()) {
         throw new ValidationError("Plugin is already registered");
       }
     }

frontend-js/src/main/js/map/data/PluginData.js

 "use strict";
 
+var Functions = require('../../Functions');
+
 /**
  *
  * @param {Object} params
@@ -36,11 +38,13 @@ PluginData.prototype.getHash = function () {
 
 /**
  *
- * @param {boolean} isPublic
+ * @param {string|boolean} isPublic
  */
 PluginData.prototype.setPublic = function (isPublic) {
   if (isPublic === null || isPublic === undefined) {
     this._public = false;
+  } else if (Functions.isString(isPublic)) {
+    this._public = (isPublic === "true");
   } else {
     this._public = isPublic;
   }

frontend-js/src/test/js/gui/admin/AddPluginDialog-test.js

@@ -5,6 +5,7 @@ require("../../mocha-config");
 var AddPluginDialog = require('../../../../main/js/gui/admin/AddPluginDialog');
 var ServerConnector = require('../../ServerConnector-mock');
 var ValidationError = require('../../../../main/js/ValidationError');
+var PluginData = require('../../../../main/js/map/data/PluginData');
 
 
 var logger = require('../../logger');
@@ -26,6 +27,12 @@ describe('AddPluginDialog', function () {
       serverConnector: ServerConnector
     });
   };
+  var getPluginsData = ServerConnector.getPluginsData;
+
+  afterEach(function () {
+    ServerConnector.getPluginsData = getPluginsData;
+  });
+
   it('init', function () {
     helper.loginAsAdmin();
     var dialog = createDialog();
@@ -85,8 +92,35 @@ describe('AddPluginDialog', function () {
         return dialog.destroy();
       });
     });
+    it('valid file exists', function () {
+      helper.loginAsAdmin();
+      var dialog = createDialog();
+      ServerConnector.getPluginsData = function () {
+        return Promise.resolve([new PluginData({urls: "./testFiles/plugin/empty.js", isPublic: "true"})]);
+      };
+      return dialog.init().then(function () {
+        $("[name='pluginUrl']").val("./testFiles/plugin/empty.js");
+        return dialog.onValidateClicked();
+      }).then(function () {
+        assert.notOk("error expected");
+      }).catch(function (e) {
+        assert.ok(e instanceof ValidationError);
+      }).finally(function () {
+        return dialog.destroy();
+      });
+    });
+    it('valid file exists as a private plugin', function () {
+      helper.loginAsAdmin();
+      var dialog = createDialog();
+      ServerConnector.getPluginsData = function () {
+        return Promise.resolve([new PluginData({urls: "./testFiles/plugin/empty.js", isPublic: "false"})]);
+      };
+      return dialog.init().then(function () {
+        $("[name='pluginUrl']").val("./testFiles/plugin/empty.js");
+        return dialog.onValidateClicked();
+      }).finally(function () {
+        return dialog.destroy();
+      });
+    });
   });
-
-
-})
-;
+});