fixes #13816 Modal dialog closes when dragging and releasing mouse button outside dialog

dist/css/bootstrap.css

@@ -5503,7 +5503,7 @@ button.close {
   right: 0;
   bottom: 0;
   left: 0;
-  z-index: 1050;
+  z-index: 1040;
   display: none;
   overflow: hidden;
   -webkit-overflow-scrolling: touch;
@@ -5551,7 +5551,6 @@ button.close {
   right: 0;
   bottom: 0;
   left: 0;
-  z-index: 1040;
   background-color: #000;
 }
 .modal-backdrop.fade {

dist/js/bootstrap.js

@@ -1015,9 +1015,8 @@ if (typeof jQuery === 'undefined') { throw new Error('Bootstrap\'s JavaScript re
       var doAnimate = $.support.transition && animate
 
       this.$backdrop = $('<div class="modal-backdrop ' + animate + '" />')
-        .appendTo(this.$body)
-
-      this.$element.on('click.dismiss.bs.modal', $.proxy(function (e) {
+        .prependTo(this.$element)
+        .on('click.dismiss.bs.modal', $.proxy(function (e) {
           if (e.target !== e.currentTarget) return
           this.options.backdrop == 'static'
             ? this.$element[0].focus.call(this.$element[0])

js/modal.js

@@ -166,9 +166,8 @@
       var doAnimate = $.support.transition && animate
 
       this.$backdrop = $('<div class="modal-backdrop ' + animate + '" />')
-        .appendTo(this.$body)
-
-      this.$element.on('click.dismiss.bs.modal', $.proxy(function (e) {
+        .prependTo(this.$element)
+        .on('click.dismiss.bs.modal', $.proxy(function (e) {
           if (e.target !== e.currentTarget) return
           this.options.backdrop == 'static'
             ? this.$element[0].focus.call(this.$element[0])

js/tests/unit/modal.js

@@ -141,7 +141,7 @@ $(function () {
         notEqual($('#modal-test').length, 0, 'modal insterted into dom')
         $('.contents').click()
         ok($('#modal-test').is(':visible'), 'modal visible')
-        $('#modal-test').click()
+        $('#modal-test .modal-backdrop').click()
       })
       .on('hidden.bs.modal', function () {
         ok(!$('#modal-test').is(':visible'), 'modal hidden')
@@ -196,7 +196,7 @@ $(function () {
     $('<div id="modal-test"><div class="contents"/></div>')
       .on('shown.bs.modal', function () {
         triggered = 0
-        $('#modal-test').click()
+        $('#modal-test .modal-backdrop').click()
       })
       .on('hide.bs.modal', function () {
         triggered += 1

less/modals.less

@@ -67,7 +67,6 @@
   right: 0;
   bottom: 0;
   left: 0;
-  z-index: @zindex-modal-background;
   background-color: @modal-backdrop-bg;
   // Fade for backdrop
   &.fade { .opacity(0); }

less/variables.less

@@ -260,8 +260,7 @@
 @zindex-popover:           1060;
 @zindex-tooltip:           1070;
 @zindex-navbar-fixed:      1030;
-@zindex-modal-background:  1040;
-@zindex-modal:             1050;
+@zindex-modal:             1040;
 
 
 //== Media queries breakpoints