From 8803eb3288861971795a627917c5c15aee8d9197 Mon Sep 17 00:00:00 2001
From: Stephen Williams <steve@icarus.com>
Date: Tue, 22 Sep 2015 16:15:41 -0700
Subject: [PATCH] Handle numeric literals with no digits.

---
 lexor.lex |  8 ++++++++
 pform.cc  | 23 ++++++++++++++---------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/lexor.lex b/lexor.lex
index d14e38694..cf86e7a57 100644
--- a/lexor.lex
+++ b/lexor.lex
@@ -862,6 +862,14 @@ verinum*make_unsized_binary(const char*txt)
       for (const char*idx = ptr ;  *idx ;  idx += 1)
 	    if (*idx != '_') size += 1;
 
+      if (size == 0) {
+	    VLerror(yylloc, "Numeric literal has no digits in it.");
+	    verinum*out = new verinum();
+	    out->has_sign(sign_flag);
+	    out->is_single(single_flag);
+	    return out;
+      }
+
       if ((based_size > 0) && (size > based_size)) yywarn(yylloc,
           "extra digits given for sized binary constant.");
 
diff --git a/pform.cc b/pform.cc
index 594026993..2f3431589 100644
--- a/pform.cc
+++ b/pform.cc
@@ -1087,16 +1087,21 @@ verinum* pform_verinum_with_size(verinum*siz, verinum*val,
 
       verinum::V pad;
 
-      switch (val->get(val->len()-1)) {
-	  case verinum::Vz:
-	    pad = verinum::Vz;
-	    break;
-	  case verinum::Vx:
+      if (val->len() == 0) {
 	    pad = verinum::Vx;
-	    break;
-	  default:
-	    pad = verinum::V0;
-	    break;
+      } else {
+
+	    switch (val->get(val->len()-1)) {
+		case verinum::Vz:
+		  pad = verinum::Vz;
+		  break;
+		case verinum::Vx:
+		  pad = verinum::Vx;
+		  break;
+		default:
+		  pad = verinum::V0;
+		  break;
+	    }
       }
 
       verinum*res = new verinum(pad, size, true);