Merge branch 'issue19217' of https://github.com/alberto/bootstrap into alberto-issue19217

1 files changed, 16 insertions, 6 deletions

diff --git a/scss/_variables.scss b/scss/_variables.scss
index 4b5af26ad..1a68a1fbf 100644
--- a/scss/_variables.scss
+++ b/scss/_variables.scss
@@ -58,12 +58,12 @@
   }
 }
 
-/// Replace `$search` with `$replace` in `$string`
-/// @author Hugo Giraudel
-/// @param {String} $string - Initial string
-/// @param {String} $search - Substring to replace
-/// @param {String} $replace ('') - New value
-/// @return {String} - Updated string
+// Replace `$search` with `$replace` in `$string`
+// @author Hugo Giraudel
+// @param {String} $string - Initial string
+// @param {String} $search - Substring to replace
+// @param {String} $replace ('') - New value
+// @return {String} - Updated string
 @function str-replace($string, $search, $replace: "") {
   $index: str-index($string, $search);
 
@@ -74,6 +74,15 @@
   @return $string;
 }
 
+@mixin _assert-starts-at-zero($map) {
+  $values: map-values($map);
+  $first-value: nth($values, 1);
+  @if $first-value != 0 {
+    @warn "First breakpoint in `$grid-breakpoints` must start at 0, but starts at #{$first-value}.";
+  }
+}
+
+
 // General variable structure
 //
 // Variable format should follow the `$component-modifier-state-property` order.
@@ -172,6 +181,7 @@ $grid-breakpoints: (
   xl: 1200px
 ) !default;
 @include _assert-ascending($grid-breakpoints, "$grid-breakpoints");
+@include _assert-starts-at-zero($grid-breakpoints);
 
 
 // 7. Grid containers