echo: fix echo -e -n "msg\n\0"

(by "Pinedo, David" <david.pinedo AT hp.com>)

diff --git a/coreutils/echo.c b/coreutils/echo.c
index 6e25db62c63efb10b17e7484a6b30cbe29602f12..cc9b9e6f4579a0132cccc6b31745c906d840808f 100644 (file)
--- a/coreutils/echo.c
+++ b/coreutils/echo.c
@@ -108,15 +108,19 @@ int echo_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                }
 #if !ENABLE_FEATURE_FANCY_ECHO
                                /* SUSv3 specifies that octal escapes must begin with '0'. */
-                               if ( (((unsigned char)*arg) - '1') >= 7)
+                               if ( ((int)(unsigned char)(*arg) - '0') >= 8) /* '8' or bigger */
 #endif
                                {
                                        /* Since SUSv3 mandates a first digit of 0, 4-digit octals
                                        * of the form \0### are accepted. */
-                                       if (*arg == '0' && ((unsigned char)(arg[1]) - '0') < 8) {
-                                               arg++;
+                                       if (*arg == '0') {
+                                               /* NB: don't turn "...\0" into "...\" */
+                                               if (arg[1] && ((unsigned char)(arg[1]) - '0') < 8) {
+                                                       arg++;
+                                               }
                                        }
-                                       /* bb_process_escape_sequence can handle nul correctly */
+                                       /* bb_process_escape_sequence handles NUL correctly
+                                        * ("...\" case). */
                                        c = bb_process_escape_sequence(&arg);
                                }
                        }

diff --git a/testsuite/echo/echo-prints-slash-zero b/testsuite/echo/echo-prints-slash-zero
new file mode 100644 (file)
index 0000000..d246632
--- /dev/null
+++ b/testsuite/echo/echo-prints-slash-zero
@@ -0,0 +1 @@
+test "`busybox echo -e -n 'msg\n\0' | od -t x1 | head -n 1`" = "0000000 6d 73 67 0a 00"