gnumeric-reader: Avoid convert_xml_string_to_value segfault on NULL string

If the 'xv' argument is null, the previous version of this code would
still dereference it.  This commit rewrites it to instead just set the
value as missing and avoid the segfault.  It also takes advantage of the
fairly recently added function value_copy_str_rpad() to eliminate some
code.

diff --git a/src/data/gnumeric-reader.c b/src/data/gnumeric-reader.c
index f166ee6aba86f1a00acefb409c466e253635a574..74911c469ea902a916f8b87ab2fd29a20dc425a6 100644 (file)
--- a/src/data/gnumeric-reader.c
+++ b/src/data/gnumeric-reader.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+   Copyright (C) 2007, 2009, 2010 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -320,21 +320,17 @@ static void
 convert_xml_string_to_value (struct ccase *c, const struct variable *var,
                             const xmlChar *xv)
 {
-  int n_bytes = 0;
   union value *v = case_data_rw (c, var);
 
-  const char *text = (const char *) xv;
-
-  if ( text)
-    n_bytes = MIN (var_get_width (var), strlen (text));
-
-  if ( var_is_alpha (var))
-    {
-      memcpy (value_str_rw (v, var_get_width (var)), text, n_bytes);
-    }
+  if (xv == NULL)
+    value_set_missing (v, var_get_width (var));
+  else if ( var_is_alpha (var))
+    value_copy_str_rpad (v, var_get_width (var), xv, ' ');
   else
     {
+      const char *text = (const char *) xv;
       char *endptr;
+
       errno = 0;
       v->f = strtod (text, &endptr);
       if ( errno != 0 || endptr == text)