Peter Eisentraut <> writes:
> So this seems to be a pretty basic bug.  Some node fields of type char
> may be zero, and so printing them as a zero byte just truncates the
> whole output string.  This could be fixed by printing chars like strings
> with the full escaping mechanism.  See attached patch.

+1 for fixing this, but you have not handled the read side correctly.
pg_strtok doesn't promise to return a null-terminated string, so without
changes, readfuncs.c would not successfully decode a zero-byte char field.
Also it would do the wrong thing for any character code that outToken had
decided to prefix with a backslash.  I think you could fix both problems
like this:

 /* Read a char field (ie, one ascii character) */
 #define READ_CHAR_FIELD(fldname) \
        token = pg_strtok(&length);             /* skip :fldname */ \
        token = pg_strtok(&length);             /* get field value */ \
-       local_node->fldname = token[0]
+       local_node->fldname = debackslash(token, length)[0]

although that's annoyingly expensive for the normal case where no
special processing is needed.  Maybe better

+       local_node->fldname = (length == 0) ? '\0' : (token[0] == '\\') ? 
token[1] : token[0]

                        regards, tom lane

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