2004-09-18  Joerg Wunsch <address@hidden>

	* libc/stdio/vfscanf.c: Fix a logical flaw that caused
	characters > 'Z' && < 'a' to be misdetected as valid
	hex digits.  Fix for bug #10420.

Index: libc/stdio/vfscanf.c
===================================================================
RCS file: /cvsroot/avr-libc/avr-libc/libc/stdio/vfscanf.c,v
retrieving revision 1.6
diff -u -u -r1.6 vfscanf.c
--- libc/stdio/vfscanf.c	21 Jul 2004 22:11:59 -0000	1.6
+++ libc/stdio/vfscanf.c	19 Sep 2004 11:21:24 -0000
@@ -374,9 +374,29 @@
 				a.ul = 0;
 				for (;;) {
 					j = tolower(i);
+					/*
+					 * First, assume it is a decimal
+					 * digit.
+					 */
 					j -= '0';
-					if (j > 9)
-						j -= 'a' - '0' - 10;
+					if (j > 9) {
+						/*
+						 * Not a decimal digit.
+						 * Try hex next.
+						 */
+						j += '0'; /* undo "- '0'"
+							   * above */
+						j -= 'a'; /* 'a' is first
+							   * hex digit */
+						if (j >= 0)
+							/* 'a' has value
+							 * 10 */
+							j += 10;
+						/*
+						 * else: not a hex digit,
+						 * gets caught below.
+						 */
+					}
 					if (j < 0 || j >= base) {
 						ungetc(i, stream);
 						break;