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, 9 insertions, 3 deletions

diff --git a/toys/posix/echo.c b/toys/posix/echo.c
index 94546ecd..70f4ce5e 100644
--- a/toys/posix/echo.c
+++ b/toys/posix/echo.c
@@ -51,7 +51,7 @@ void echo_main(void)
 
     // Should we output arg verbatim?
 
-    if (!(toys.optflags & FLAG_e)) {
+    if (!FLAG(e)) {
       xprintf("%s", arg);
       continue;
     }
@@ -79,7 +79,13 @@ void echo_main(void)
               if (temp>='a' && temp<='f') {
                 out = (out*16)+temp-'a'+10;
                 c++;
-              } else break;
+              } else {
+                if (n==1) {
+                  --c;
+                  out = '\\';
+                }
+                break;
+              }
             }
           }
         // Slash in front of unknown character, print literal.
@@ -90,5 +96,5 @@ void echo_main(void)
   }
 
   // Output "\n" if no -n
-  if (!(toys.optflags&FLAG_n)) putchar('\n');
+  if (!FLAG(n)) putchar('\n');
 }