Fix bogus code in contrib/ tsearch dictionary examples.

Both dict_int and dict_xsyn were blithely assuming that whatever memory
palloc gives back will be pre-zeroed.  This would typically work for
just about long enough to run their regression tests, and no longer :-(.

The pre-9.0 code in dict_xsyn was even lamer than that, as it would
happily give back a pointer to the result of palloc(0), encouraging
its caller to access off the end of memory.  Again, this would just
barely fail to fail as long as memory contained nothing but zeroes.

Per a report from Rodrigo Hjort that code based on these examples
didn't work reliably.

diff --git a/contrib/dict_int/dict_int.c b/contrib/dict_int/dict_int.c
index 9f61447160585a1b61a2b681bfa28b64906bb131..68964548a68dc41d88893606d7ba70f8d76a3ac8 100644 (file)
--- a/contrib/dict_int/dict_int.c
+++ b/contrib/dict_int/dict_int.c
@@ -72,7 +72,7 @@ dintdict_lexize(PG_FUNCTION_ARGS)
    DictInt    *d = (DictInt *) PG_GETARG_POINTER(0);
    char       *in = (char *) PG_GETARG_POINTER(1);
    char       *txt = pnstrdup(in, PG_GETARG_INT32(2));
-   TSLexeme   *res = palloc(sizeof(TSLexeme) * 2);
+   TSLexeme   *res = palloc0(sizeof(TSLexeme) * 2);
 
    res[1].lexeme = NULL;
    if (PG_GETARG_INT32(2) > d->maxlen)

diff --git a/contrib/dict_xsyn/dict_xsyn.c b/contrib/dict_xsyn/dict_xsyn.c
index 3c05a1ea908639d5a5b8b763a8af25cbe3aa9d53..d47315bd793fb9955d488a0e51ab2fdd94c736e3 100644 (file)
--- a/contrib/dict_xsyn/dict_xsyn.c
+++ b/contrib/dict_xsyn/dict_xsyn.c
@@ -244,6 +244,8 @@ dxsyn_lexize(PG_FUNCTION_ARGS)
            if (pos != value || d->keeporig)
            {
                res[nsyns].lexeme = pnstrdup(syn, end - syn);
+               res[nsyns].nvariant = 0;
+               res[nsyns].flags = 0;
                nsyns++;
            }