From c91f8f846c3c4e048b89e5479562bf224aac04f1 Mon Sep 17 00:00:00 2001
From: Volker Berlin <volker.berlin@googlemail.com>
Date: Sat, 19 Nov 2016 18:08:30 +0100
Subject: [PATCH] implements "@import (optional)"

---
 src/com/inet/lib/less/LessParser.java                |  6 +++++-
 .../inet/lib/less/samples/general/importOptional.css | 12 ++++++++++++
 .../lib/less/samples/general/importOptional.less     |  2 ++
 3 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 test/com/inet/lib/less/samples/general/importOptional.css
 create mode 100644 test/com/inet/lib/less/samples/general/importOptional.less

diff --git a/src/com/inet/lib/less/LessParser.java b/src/com/inet/lib/less/LessParser.java
index 95d0fa24..b7165af7 100644
--- a/src/com/inet/lib/less/LessParser.java
+++ b/src/com/inet/lib/less/LessParser.java
@@ -26,6 +26,7 @@
  */
 package com.inet.lib.less;
 
+import java.io.IOException;
 import java.io.Reader;
 import java.net.MalformedURLException;
 import java.net.URL;
@@ -450,7 +451,6 @@ private void importFile( FormattableContainer currentRule, final String name ) {
                             break;
                         case "optional":
                             isOptional = true;
-                            System.err.println( "not implemented @import keyword: " + keywordStr ); //TODO
                             break;
                         case "once":
                             isMultiple = false;
@@ -577,6 +577,10 @@ private void importFile( FormattableContainer currentRule, final String name ) {
             }
         } catch( LessException ex ) {
             throw ex;
+        } catch( IOException ex ) {
+            if( !isOptional ) {
+                throw new LessException( ex );
+            }
         } catch( Exception ex ) {
             throw new LessException( ex );
         } finally {
diff --git a/test/com/inet/lib/less/samples/general/importOptional.css b/test/com/inet/lib/less/samples/general/importOptional.css
new file mode 100644
index 00000000..b3bba7f6
--- /dev/null
+++ b/test/com/inet/lib/less/samples/general/importOptional.css
@@ -0,0 +1,12 @@
+.slash {
+  a: 1.5;
+  b: 1.5;
+  e: a / b;
+  f: a / b;
+  g: a / b;
+  h: a / b;
+}
+.slash2 {
+  background: url("img.jpg") center / 100px;
+  background: url(abc/img.jpg);
+}
diff --git a/test/com/inet/lib/less/samples/general/importOptional.less b/test/com/inet/lib/less/samples/general/importOptional.less
new file mode 100644
index 00000000..73e74358
--- /dev/null
+++ b/test/com/inet/lib/less/samples/general/importOptional.less
@@ -0,0 +1,2 @@
+@import (optional) "DoesNotExists.less";
+@import (optional) "slash.less";