css-url.c (get_uri_string): Fix regression from 8e6de1fb5

Solves the issue discovered by Gabriel Somlo and reported in the ml thread
"Regression in git master branch (commit 8e6de1fb5f)"

ChangeLog

@@ -1,3 +1,7 @@
+2013-10-22  Ángel González <keisial@gmail.com>
+
+	* bootstrap.conf (gnulib_modules): Add module xstrndup.
+
 2014-09-25  Tim Ruehsen <tim.ruehsen@gmx.de>
 
 	* configure.ac: removed WgetTest.pm.in

bootstrap.conf

@@ -78,6 +78,7 @@ update-copyright
 vasprintf
 vsnprintf
 write
+xstrndup
 "
 
 gnulib_extra_files="

src/ChangeLog

@@ -1,3 +1,7 @@
+2013-10-22  Ángel González <keisial@gmail.com>
+
+	* css-url.c (get_uri_string): Honor the specified length argument.
+
 2014-10-16  Tim Ruehsen  <tim.ruehsen@gmx.de>
 
 	* url.c (url_parse): little code cleanup

src/css-url.c

@@ -52,6 +52,7 @@ as that of the covered work.  */
 #include "html-url.h"
 #include "css-tokens.h"
 #include "css-url.h"
+#include "xstrndup.h"
 
 /* from lex.yy.c */
 extern char *yytext;
@@ -97,7 +98,7 @@ get_uri_string (const char *at, int *pos, int *length)
       *length -= 2;
     }
 
-  return xstrdup (at + *pos);
+  return xstrndup (at + *pos, *length);
 }
 
 void