Give appropriate error messages when the user tries to use an blank master password. Fixes #4341

docs/en_US/release_notes_4_15.rst

@@ -20,6 +20,7 @@ Bug fixes
 
 | `Issue #3789 <https://redmine.postgresql.org/issues/3789>`_ -  Ensure context menus never get hidden below the menu bar.
 | `Issue #3913 <https://redmine.postgresql.org/issues/3913>`_ -  Ensure the correct "running at" agent is shown when a pgAgent job is executing.
+| `Issue #4341 <https://redmine.postgresql.org/issues/4341>`_ -  Give appropriate error messages when the user tries to use an blank master password.
 | `Issue #4459 <https://redmine.postgresql.org/issues/4459>`_ -  Don't quote bigints when copying them from the Query Tool results grid.
 | `Issue #4482 <https://redmine.postgresql.org/issues/4482>`_ -  Ensure compression level is passed to pg_dump when backing up in directory format.
 | `Issue #4483 <https://redmine.postgresql.org/issues/4483>`_ -  Ensure the number of jobs can be specified when backing up in directory format.

web/pgadmin/browser/__init__.py

@@ -792,15 +792,16 @@ def set_master_password():
     # Master password is not applicable for server mode
     if not config.SERVER_MODE and config.MASTER_PASSWORD_REQUIRED:
 
+        # if master pass is set previously
+        if current_user.masterpass_check is not None:
+            if data.get('button_click') and not validate_master_password(data.get('password')):
+                return form_master_password_response(
+                    existing=True,
+                    present=False,
+                    errmsg=gettext("Incorrect master password")
+                )
+
         if data != '' and data.get('password', '') != '':
-            # if master pass is set previously
-            if current_user.masterpass_check is not None:
-                if not validate_master_password(data.get('password')):
-                    return form_master_password_response(
-                        existing=True,
-                        present=False,
-                        errmsg=gettext("Incorrect master password")
-                    )
 
             # store the master pass in the memory
             set_crypt_key(data.get('password'))
@@ -827,9 +828,14 @@ def set_master_password():
                 present=False,
             )
         elif not get_crypt_key()[0]:
+            error_message = None
+            if data.get('button_click') and data.get('password') == '':
+                # If user attempted to enter a blank password, then throw error
+                error_message = gettext("Master password cannot be empty")
             return form_master_password_response(
                 existing=False,
                 present=False,
+                errmsg=error_message
             )
 
     # if master password is disabled now, but was used once then

web/pgadmin/browser/static/js/browser.js

@@ -605,7 +605,7 @@ define('pgadmin.browser', [
                 /* OK Button */
                 self.set_master_password(
                   $('#frmMasterPassword #password').val(),
-                  parentDialog.set_callback,
+                  true,parentDialog.set_callback,
                 );
               } else if(event.index == 2) {
                 /* Cancel button */
@@ -677,12 +677,13 @@ define('pgadmin.browser', [
       });
     },
 
-    set_master_password: function(password='', set_callback=()=>{}) {
+    set_master_password: function(password='', button_click=false, set_callback=()=>{}) {
       let data=null, self = this;
 
       if(password != null || password!='') {
         data = JSON.stringify({
           'password': password,
+          'button_click': button_click,
         });
       }