43261: Fix unary minus with base.

Apply unary minus to a complete lexical constant rather than the
first component that comes along.

ChangeLog

@@ -1,3 +1,8 @@
+2018-08-08  Peter Stephenson  <p.stephenson@samsung.com>
+
+	* 43261: Src/math.c, Test/C01arith.ztst: Apply unary minus to
+	entire lexical constant, so base doesn't get treated as negative.
+
 2018-08-07  Peter Stephenson  <p.stephenson@samsung.com>
 
 	* Anton Shestakov: 43254: Completion/Unix/Command/_hg: Remove hg

Src/math.c

@@ -640,8 +640,19 @@ zzlex(void)
 	    }
 	    if (unary) {
 		if (idigit(*ptr) || *ptr == '.') {
-		    ptr--;
-		    return lexconstant();
+		    int ctype = lexconstant();
+		    if (ctype == NUM)
+		    {
+			if (yyval.type == MN_FLOAT)
+			{
+			    yyval.u.d = -yyval.u.d;
+			}
+			else
+			{
+			    yyval.u.l = -yyval.u.l;
+			}
+		    }
+		    return ctype;
 		} else
 		    return UMINUS;
 	    } else

Test/C01arith.ztst

@@ -467,3 +467,7 @@
 >6
 >4
 ?(eval):6: bad math expression: lvalue required
+
+  print $(( -2#101-16#f ))
+0: Unary minus doesn't apply to base but to number as a whole.
+>-20