Support indentation of detached Less CSS rulesets

* lisp/textmodes/css-mode.el (css-smie-rules): Provide better support
for indentation of detached rulesets passed to Less mixins.

* test/manual/indent/less-css-mode.less: New file.

1 files changed, 29 insertions, 0 deletions

diff --git a/test/manual/indent/less-css-mode.less b/test/manual/indent/less-css-mode.less
new file mode 100644
index 00000000000..36c037450cc
--- /dev/null
+++ b/test/manual/indent/less-css-mode.less
@@ -0,0 +1,29 @@
+.desktop-and-old-ie(@rules) {
+    @media screen and (min-width: 1200) { @rules(); }
+    html.lt-ie9 &                       { @rules(); }
+}
+
+header {
+    background-color: blue;
+
+    .desktop-and-old-ie({
+        background-color: red;
+    });
+}
+
+.e(@name, @rules) {
+    &__@{name} { @rules(); }
+}
+
+.m(@name, @rules) {
+    &--@{name} { @rules(); }
+}
+
+.btn {
+    .e(span, {  // .btn__span
+        display: inline-block;
+    });
+    .m(primary, { // .btn--primary
+        background: blue;
+    });
+}