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Make replace(), split_part(), and string_to_array() behave somewhat sanely

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when handed an invalidly-encoded pattern.  The previous coding could get
into an infinite loop if pg_mb2wchar_with_len() returned a zero-length
string after we'd tested for nonempty pattern; which is exactly what it
will do if the string consists only of an incomplete multibyte character.
This led to either an out-of-memory error or a backend crash depending
on platform.  Per report from Wiktor Wodecki.
This commit is contained in:
Tom Lane
2007-07-19 20:34:34 +00:00
parent fbbc0f05f1
commit a0b2bb8ced
1 changed files with 54 additions and 14 deletions
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68
src/backend/utils/adt/varlena.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.139.2.4 2006/10/07 00:11:59 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.139.2.5 2007/07/19 20:34:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -2076,8 +2076,8 @@ replace_text(PG_FUNCTION_ARGS)
text *src_text = PG_GETARG_TEXT_P(0);
text *from_sub_text = PG_GETARG_TEXT_P(1);
text *to_sub_text = PG_GETARG_TEXT_P(2);
int src_text_len = TEXTLEN(src_text);
int from_sub_text_len = TEXTLEN(from_sub_text);
int src_text_len;
int from_sub_text_len;
TextPositionState state;
text *chunk_text;
text *ret_text;
@ -2085,11 +2085,22 @@ replace_text(PG_FUNCTION_ARGS)
int curr_posn;
StringInfoData str;
if (src_text_len == 0 || from_sub_text_len == 0)
PG_RETURN_TEXT_P(src_text);
text_position_setup(src_text, from_sub_text, &state);
/*
* Note: we check the converted string length, not the original, because
* they could be different if the input contained invalid encoding.
*/
src_text_len = state.len1;
from_sub_text_len = state.len2;
/* Return unmodified source string if empty source or pattern */
if (src_text_len < 1 || from_sub_text_len < 1)
{
text_position_cleanup(&state);
PG_RETURN_TEXT_P(src_text);
}
start_posn = 1;
curr_posn = text_position_next(1, &state);
@ -2104,6 +2115,9 @@ replace_text(PG_FUNCTION_ARGS)
do
{
CHECK_FOR_INTERRUPTS();
/* copy the data skipped over by last text_position_next() */
chunk_text = text_substring(PointerGetDatum(src_text),
start_posn,
curr_posn - start_posn,
@ -2396,8 +2410,8 @@ split_text(PG_FUNCTION_ARGS)
text *inputstring = PG_GETARG_TEXT_P(0);
text *fldsep = PG_GETARG_TEXT_P(1);
int fldnum = PG_GETARG_INT32(2);
int inputstring_len = TEXTLEN(inputstring);
int fldsep_len = TEXTLEN(fldsep);
int inputstring_len;
int fldsep_len;
TextPositionState state;
int start_posn;
int end_posn;
@ -2409,13 +2423,26 @@ split_text(PG_FUNCTION_ARGS)
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("field position must be greater than zero")));
text_position_setup(inputstring, fldsep, &state);
/*
* Note: we check the converted string length, not the original, because
* they could be different if the input contained invalid encoding.
*/
inputstring_len = state.len1;
fldsep_len = state.len2;
/* return empty string for empty input string */
if (inputstring_len < 1)
{
text_position_cleanup(&state);
PG_RETURN_TEXT_P(PG_STR_GET_TEXT(""));
}
/* empty field separator */
if (fldsep_len < 1)
{
text_position_cleanup(&state);
/* if first field, return input string, else empty string */
if (fldnum == 1)
PG_RETURN_TEXT_P(inputstring);
@ -2423,8 +2450,6 @@ split_text(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(PG_STR_GET_TEXT(""));
}
text_position_setup(inputstring, fldsep, &state);
/* identify bounds of first field */
start_posn = 1;
end_posn = text_position_next(1, &state);
@ -2484,8 +2509,8 @@ text_to_array(PG_FUNCTION_ARGS)
{
text *inputstring = PG_GETARG_TEXT_P(0);
text *fldsep = PG_GETARG_TEXT_P(1);
int inputstring_len = TEXTLEN(inputstring);
int fldsep_len = TEXTLEN(fldsep);
int inputstring_len;
int fldsep_len;
TextPositionState state;
int fldnum;
int start_posn;
@ -2493,23 +2518,38 @@ text_to_array(PG_FUNCTION_ARGS)
text *result_text;
ArrayBuildState *astate = NULL;
text_position_setup(inputstring, fldsep, &state);
/*
* Note: we check the converted string length, not the original, because
* they could be different if the input contained invalid encoding.
*/
inputstring_len = state.len1;
fldsep_len = state.len2;
/* return NULL for empty input string */
if (inputstring_len < 1)
{
text_position_cleanup(&state);
PG_RETURN_NULL();
}
/*
* empty field separator return one element, 1D, array using the input
* string
*/
if (fldsep_len < 1)
{
text_position_cleanup(&state);
PG_RETURN_ARRAYTYPE_P(create_singleton_array(fcinfo, TEXTOID,
PointerGetDatum(inputstring), 1));
text_position_setup(inputstring, fldsep, &state);
}
start_posn = 1;
for (fldnum = 1;; fldnum++) /* field number is 1 based */
{
CHECK_FOR_INTERRUPTS();
end_posn = text_position_next(start_posn, &state);
if (end_posn == 0)