Merge branch 'master' into v4

Conflicts:
	.gitignore
	Gruntfile.js
	_config.yml
	dist/css/bootstrap-theme.css
	dist/css/bootstrap-theme.min.css
	dist/css/bootstrap.css
	dist/css/bootstrap.css.map
	dist/css/bootstrap.min.css
	dist/js/bootstrap.js
	dist/js/bootstrap.min.js
	docs/_includes/components/navbar.html
	docs/_includes/components/progress-bars.html
	docs/_includes/css/grid.html
	docs/_includes/css/overview.html
	docs/_includes/customizer-variables.html
	docs/_includes/getting-started/accessibility.html
	docs/_includes/getting-started/browser-device-support.html
	docs/_includes/getting-started/community.html
	docs/_includes/getting-started/disabling-responsiveness.html
	docs/_includes/getting-started/download.html
	docs/_includes/getting-started/examples.html
	docs/_includes/getting-started/license.html
	docs/_includes/getting-started/third-party-support.html
	docs/_includes/js/alerts.html
	docs/_includes/js/buttons.html
	docs/_includes/js/carousel.html
	docs/_includes/js/collapse.html
	docs/_includes/js/dropdowns.html
	docs/_includes/js/modal.html
	docs/_includes/js/popovers.html
	docs/_includes/js/scrollspy.html
	docs/_includes/js/tabs.html
	docs/_includes/js/tooltips.html
	docs/_includes/js/transitions.html
	docs/_includes/nav/javascript.html
	docs/_includes/nav/main.html
	docs/about.html
	docs/assets/css/docs.min.css
	docs/assets/css/src/docs.css
	docs/assets/js/customize.min.js
	docs/assets/js/raw-files.min.js
	docs/assets/js/src/customizer.js
	docs/dist/css/bootstrap-theme.css
	docs/dist/css/bootstrap-theme.min.css
	docs/dist/css/bootstrap.css
	docs/dist/css/bootstrap.css.map
	docs/dist/css/bootstrap.min.css
	docs/dist/js/bootstrap.js
	docs/dist/js/bootstrap.min.js
	docs/migration.html
	js/affix.js
	js/alert.js
	js/button.js
	js/carousel.js
	js/collapse.js
	js/dropdown.js
	js/modal.js
	js/popover.js
	js/scrollspy.js
	js/tab.js
	js/tests/unit/affix.js
	js/tests/unit/button.js
	js/tests/unit/carousel.js
	js/tests/unit/modal.js
	js/tests/unit/tooltip.js
	js/tests/visual/modal.html
	js/tooltip.js
	less/component-animations.less
	less/jumbotron.less
	less/mixins/background-variant.less
	less/mixins/buttons.less
	less/mixins/responsive-visibility.less
	less/mixins/text-emphasis.less
	less/navbar.less
	less/navs.less
	less/scaffolding.less
	less/tooltip.less
	less/utilities.less
	less/variables.less
	package.json
	scss/_buttons.scss
	scss/_forms.scss
	scss/_modal.scss

11 files changed, 33 insertions, 12 deletions

diff --git a/scss/_buttons.scss b/scss/_buttons.scss
index 5f4b3bc426..b33081868b 100644
--- a/scss/_buttons.scss
+++ b/scss/_buttons.scss
@@ -46,11 +46,17 @@
   &.disabled,
   &:disabled,
   fieldset[disabled] & {
-    pointer-events: none; // Future-proof disabling of clicks
     cursor: $cursor-disabled;
     opacity: .65;
     @include box-shadow(none);
   }
+
+  a& {
+    &.disabled,
+    fieldset[disabled] & {
+      pointer-events: none; // Future-proof disabling of clicks on `<a>` elements
+    }
+  }
 }
 
 
diff --git a/scss/_forms.scss b/scss/_forms.scss
index 4e0a45f9f1..8b58835a7b 100644
--- a/scss/_forms.scss
+++ b/scss/_forms.scss
@@ -377,12 +377,14 @@ input[type="checkbox"] {
   text-align: center;
   pointer-events: none;
 }
-.input-lg + .form-control-feedback {
+.input-lg + .form-control-feedback,
+.input-group-lg + .form-control-feedback {
   width: $input-height-lg;
   height: $input-height-lg;
   line-height: $input-height-lg;
 }
-.input-sm + .form-control-feedback {
+.input-sm + .form-control-feedback,
+.input-group-sm + .form-control-feedback {
   width: $input-height-sm;
   height: $input-height-sm;
   line-height: $input-height-sm;
diff --git a/scss/_jumbotron.scss b/scss/_jumbotron.scss
index f826cd6160..d60793efd2 100644
--- a/scss/_jumbotron.scss
+++ b/scss/_jumbotron.scss
@@ -25,7 +25,7 @@
   }
 
   .jumbotron-heading {
-    font-size: ($font-size-base * 4.5);
+    font-size: $jumbotron-heading-font-size;
   }
 }
 
diff --git a/scss/_modal.scss b/scss/_modal.scss
index da3b90c0b4..ac27613767 100644
--- a/scss/_modal.scss
+++ b/scss/_modal.scss
@@ -59,11 +59,14 @@
 
 // Modal background
 .modal-backdrop {
-  position: absolute;
+  position: fixed;
   top: 0;
   right: 0;
+  bottom: 0;
   left: 0;
   background-color: $modal-backdrop-bg;
+  z-index: $zindex-modal-bg;
+
   // Fade for backdrop
   &.fade { opacity: 0; }
   &.in { opacity: $modal-backdrop-opacity; }
diff --git a/scss/_nav.scss b/scss/_nav.scss
index 3d27891be7..228613cfe6 100644
--- a/scss/_nav.scss
+++ b/scss/_nav.scss
@@ -137,11 +137,9 @@
 .tab-content {
   > .tab-pane {
     display: none;
-    visibility: hidden;
   }
   > .active {
     display: block;
-    visibility: visible;
   }
 }
 
diff --git a/scss/_scaffolding.scss b/scss/_scaffolding.scss
index 27e09e96f6..9b93010bac 100644
--- a/scss/_scaffolding.scss
+++ b/scss/_scaffolding.scss
@@ -158,3 +158,14 @@ hr {
     clip: auto;
   }
 }
+
+// iOS "clickable elements" fix for role="button"
+//
+// Fixes "clickability" issue (and more generally, the firing of events such as focus as well)
+// for traditionally non-focusable elements with role="button"
+// see https://developer.mozilla.org/en-US/docs/Web/Events/click#Safari_Mobile
+// Upstream patch for normalize.css submitted: https://github.com/necolas/normalize.css/pull/379 - remove this fix once that is merged
+
+[role="button"] {
+  cursor: pointer;
+}
diff --git a/scss/_tooltip.scss b/scss/_tooltip.scss
index 00c6049b85..379d6d5e60 100644
--- a/scss/_tooltip.scss
+++ b/scss/_tooltip.scss
@@ -13,7 +13,6 @@
   font-size: $font-size-sm;
   font-weight: normal;
   line-height: 1.4;
-  visibility: visible;
   opacity: 0;
 
   &.in { opacity: $tooltip-opacity; }
diff --git a/scss/_variables.scss b/scss/_variables.scss
index 4119526be3..4b78edb197 100644
--- a/scss/_variables.scss
+++ b/scss/_variables.scss
@@ -225,7 +225,8 @@ $zindex-dropdown:          1000 !default;
 $zindex-popover:           1060 !default;
 $zindex-tooltip:           1070 !default;
 $zindex-navbar-fixed:      1030 !default;
-$zindex-modal:             1040 !default;
+$zindex-modal-bg:          1040 !default;
+$zindex-modal:             1050 !default;
 
 
 // Media queries breakpoints
@@ -385,6 +386,7 @@ $jumbotron-padding:              2rem !default;
 $jumbotron-color:                inherit !default;
 $jumbotron-bg:                   $gray-lighter !default;
 $jumbotron-heading-color:        inherit !default;
+$jumbotron-heading-font-size:    ($font-size-base * 4.5) !default;
 // $jumbotron-font-size:            ceil(($font-size-base * 1.5)) !default;
 
 
diff --git a/scss/mixins/_background-variant.scss b/scss/mixins/_background-variant.scss
index 577f019ca2..3287d7a060 100644
--- a/scss/mixins/_background-variant.scss
+++ b/scss/mixins/_background-variant.scss
@@ -6,7 +6,7 @@
     background-color: $color;
   }
   a#{$parent} {
-    @include hover {
+    @include hover-focus {
       background-color: darken($color, 10%);
     }
   }
diff --git a/scss/mixins/_responsive-visibility.scss b/scss/mixins/_responsive-visibility.scss
index 9867db013d..cbdf777239 100644
--- a/scss/mixins/_responsive-visibility.scss
+++ b/scss/mixins/_responsive-visibility.scss
@@ -7,7 +7,7 @@
   #{$parent} {
     display: block !important;
   }
-  table#{$parent}  { display: table; }
+  table#{$parent}  { display: table !important; }
   tr#{$parent}     { display: table-row !important; }
   th#{$parent},
   td#{$parent}     { display: table-cell !important; }
diff --git a/scss/mixins/_text-emphasis.scss b/scss/mixins/_text-emphasis.scss
index ab3869d31e..0a6428ea76 100644
--- a/scss/mixins/_text-emphasis.scss
+++ b/scss/mixins/_text-emphasis.scss
@@ -5,7 +5,7 @@
     color: $color;
   }
   a#{$parent} {
-    @include hover {
+    @include hover-focus {
       color: darken($color, 10%);
     }
   }