[BusyBox] busybox-1-0pre2 sed problem

[Jean Wolter]

Hello,

I am not quite sure what the right behaviour should be, but the
following command IMHO doesn't produce the right output:

echo foobar | sed -n 's/foo//;s/bar/found/p'
found
echo fooba | sed -n 's/foo//;s/bar/found/p'
ba

It always prints the pattern space if the first substition changed the
pattern space. The manual says:

    `p'
          If the substitution was made, then print the new pattern
          space.

But since the second substitution wasn't made it shouldn't print
anything.

A simple fix for this specific problem would be to simply reset the
altered flag before executing a single command:

--- editors/sed.c       23 Aug 2003 09:31:46 -0000      1.1.1.1
+++ editors/sed.c       23 Aug 2003 22:17:58 -0000
@@ -840,6 +840,7 @@
                                        && (next_line == NULL))
                                );
 
+                       altered = 0;
                        if (sed_cmd->cmd == '{') {
                                block_mask = block_mask & matched;
                        }

regards,
Jean