echo/printf: expand test cases, fix \x corner cases.

The behavior with "\xAV" (where the second hex digit is invalid) is
different from the behavior with "\xVA", and echo and printf differ from
each other.

1 files changed, 4 insertions, 7 deletions

diff --git a/toys/posix/printf.c b/toys/posix/printf.c
index 5448d8c7..b51eddc0 100644
--- a/toys/posix/printf.c
+++ b/toys/posix/printf.c
@@ -9,12 +9,12 @@
 
 USE_PRINTF(NEWTOY(printf, "<1?^", TOYFLAG_USR|TOYFLAG_BIN))
 
-config PRINTF 
+config PRINTF
   bool "printf"
   default y
   help
     usage: printf FORMAT [ARGUMENT...]
-    
+
     Format and print ARGUMENT(s) according to FORMAT, using C printf syntax
     (% escapes for cdeEfgGiosuxX, \ escapes for abefnrtv0 or \OCTAL or \xHEX).
 */
@@ -61,11 +61,8 @@ static int handle_slash(char **esc_val, int posix)
     num = tolower(*ptr) - '0';
     if (num >= 'a'-'0') num += '0'-'a'+10;
     if (num >= base) {
-      // Don't parse invalid hex value ala "\xvd", print it verbatim
-      if (base == 16 && len == 2) {
-        ptr--;
-        result = '\\';
-      }
+      // "\xav" is "\xa"+"v", but "\xva" is an error.
+      if (base == 16 && len == 2) error_exit("bad \\x");
       break;
     }
     result = (result*base)+num;