Fixes #3191

lib/less/contexts.js

@@ -62,6 +62,21 @@ contexts.Eval = function(options, frames) {
     this.importantScope = this.importantScope || [];
 };
 
+contexts.Eval.prototype.enterCalc = function () {
+    if (!this.calcStack) {
+        this.calcStack = [];
+    }
+    this.calcStack.push(true);
+    this.inCalc = true;
+};
+
+contexts.Eval.prototype.exitCalc = function () {
+    this.calcStack.pop();
+    if (!this.calcStack) {
+        this.inCalc = false;
+    }
+};
+
 contexts.Eval.prototype.inParenthesis = function () {
     if (!this.parensStack) {
         this.parensStack = [];
@@ -73,6 +88,7 @@ contexts.Eval.prototype.outOfParenthesis = function () {
     this.parensStack.pop();
 };
 
+contexts.Eval.prototype.inCalc = false;
 contexts.Eval.prototype.mathOn = true;
 contexts.Eval.prototype.isMathOn = function () {
     if (!this.mathOn) {

lib/less/parser/parser.js

@@ -351,13 +351,17 @@ var Parser = function Parser(context, imports, fileInfo) {
                 //
                 //     "milky way" 'he\'s the one!'
                 //
-                quoted: function () {
+                quoted: function (forceEscaped) {
                     var str, index = parserInput.i, isEscaped = false;
 
                     parserInput.save();
                     if (parserInput.$char("~")) {
                         isEscaped = true;
+                    } else if (forceEscaped) {
+                        parserInput.restore();
+                        return;
                     }
+
                     str = parserInput.$quoted();
                     if (!str) {
                         parserInput.restore();
@@ -1883,7 +1887,7 @@ var Parser = function Parser(context, imports, fileInfo) {
                 var o = this.sub() || entities.dimension() ||
                         entities.color() || entities.variable() ||
                         entities.property() || entities.call() ||
-                        entities.colorKeyword();
+                        entities.quoted(true) || entities.colorKeyword();
 
                 if (negate) {
                     o.parensInOp = true;

lib/less/tree/call.js

@@ -7,7 +7,7 @@ var Node = require("./node"),
 var Call = function (name, args, index, currentFileInfo) {
     this.name = name;
     this.args = args;
-    this.mathOn = name === 'calc' ? false : true;
+    this.calc = name === 'calc';
     this._index = index;
     this._fileInfo = currentFileInfo;
 };
@@ -30,13 +30,18 @@ Call.prototype.accept = function (visitor) {
 // The function should receive the value, not the variable.
 //
 Call.prototype.eval = function (context) {
-
     /**
      * Turn off math for calc(), and switch back on for evaluating nested functions
      */
     var currentMathContext = context.mathOn;
-    context.mathOn = this.mathOn;
+    context.mathOn = !this.calc;
+    if (this.calc || context.inCalc) {
+        context.enterCalc();
+    }
     var args = this.args.map(function (a) { return a.eval(context); });
+    if (this.calc || context.inCalc) {
+        context.exitCalc();
+    }
     context.mathOn = currentMathContext;
 
     var result, funcCaller = new FunctionCaller(this.name, context, this.getIndex(), this.fileInfo());

lib/less/tree/expression.js

@@ -15,6 +15,7 @@ Expression.prototype.accept = function (visitor) {
 };
 Expression.prototype.eval = function (context) {
     var returnValue,
+        mathOn = context.isMathOn(),
         inParenthesis = this.parens && !this.parensInOp,
         doubleParen = false;
     if (inParenthesis) {
@@ -25,7 +26,7 @@ Expression.prototype.eval = function (context) {
             return e.eval(context);
         }));
     } else if (this.value.length === 1) {
-        if (this.value[0].parens && !this.value[0].parensInOp) {
+        if (this.value[0].parens && !this.value[0].parensInOp && !context.inCalc) {
             doubleParen = true;
         }
         returnValue = this.value[0].eval(context);
@@ -35,7 +36,7 @@ Expression.prototype.eval = function (context) {
     if (inParenthesis) {
         context.outOfParenthesis();
     }
-    if (this.parens && this.parensInOp && !(context.isMathOn()) && !doubleParen) {
+    if (this.parens && this.parensInOp && !mathOn && !doubleParen) {
         returnValue = new Paren(returnValue);
     }
     return returnValue;

test/css/calc.css

@@ -1,5 +1,17 @@
 .no-math {
   width: calc(50% + (25vh - 20px));
+  height: calc(50% + (25vh - 20px));
+  min-height: calc((10vh) + calc(5vh));
   foo: 3 calc(3 + 4) 11;
   bar: calc(1 + 20%);
 }
+.b {
+  one: calc(100% - (20px));
+  two: calc(100% - (10px + 10px));
+  three: calc(100% - (3 * 1));
+  four: calc(100% - (3 * 1));
+  nested: calc(calc(2.25rem + 2px) - 1px * 2);
+}
+.c {
+  height: calc(100% - ((10px * 3) + (10px * 2)));
+}

test/less/calc.less

@@ -1,7 +1,25 @@
 .no-math {
   @var: 50vh/2;
   width: calc(50% + (@var - 20px));
+  height: calc(50% + ((@var - 20px)));
+  min-height: calc(((10vh)) + calc((5vh)));
   foo: 1 + 2 calc(3 + 4) 5 + 6;
   @floor: floor(1 + .1);
   bar: calc(@floor + 20%);
+}
+
+.b {
+  @a: 10px;
+  @b: 10px;
+
+  one: calc(100% - ((min(@a + @b))));
+  two: calc(100% - (((@a + @b))));
+  three: calc(e('100%') - (3 * 1));
+  four: calc(~'100%' - (3 * 1));
+  nested: calc(calc(2.25rem + 2px) - 1px * 2);
+}
+
+.c {
+  @v: 10px;
+  height: calc(100% - ((@v * 3) + (@v * 2)));
 }