Fix a *second* buffer overrun bug in to_ascii(). Grumble.

diff --git a/src/backend/utils/adt/ascii.c b/src/backend/utils/adt/ascii.c
index 9595876286b86dd6feb08767eb79a04b7f7f89c8..0091ead7d3b1003f4687114a647e8b1a76cb92f9 100644 (file)
--- a/src/backend/utils/adt/ascii.c
+++ b/src/backend/utils/adt/ascii.c
@@ -1,31 +1,31 @@
-/* -----------------------------------------------------------------------
+/*-----------------------------------------------------------------------
  * ascii.c
+ *      The PostgreSQL routine for string to ascii conversion.
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/ascii.c,v 1.14 2003/04/02 21:07:59 tgl Exp $
- *
- *      Portions Copyright (c) 1999-2000, PostgreSQL Global Development Group
- *
+ *      Portions Copyright (c) 1999-2002, PostgreSQL Global Development Group
  *
- *      TO_ASCII()
+ * IDENTIFICATION
+ *       $Header: /cvsroot/pgsql/src/backend/utils/adt/ascii.c,v 1.15 2003/07/14 16:41:38 tgl Exp $
  *
- *      The PostgreSQL routine for string to ascii conversion.
- *
- * -----------------------------------------------------------------------
+ *-----------------------------------------------------------------------
  */
-
 #include "postgres.h"
+
 #include "utils/builtins.h"
 #include "mb/pg_wchar.h"
 #include "utils/ascii.h"
 
+static void pg_to_ascii(unsigned char *src, unsigned char *src_end,
+                                               unsigned char *dest, int enc);
 static text *encode_to_ascii(text *data, int enc);
 
+
 /* ----------
  * to_ascii
  * ----------
  */
-char *
-pg_to_ascii(unsigned char *src, unsigned char *src_end, unsigned char *desc, int enc)
+static void
+pg_to_ascii(unsigned char *src, unsigned char *src_end, unsigned char *dest, int enc)
 {
        unsigned char *x;
        unsigned char *ascii;
@@ -37,7 +37,6 @@ pg_to_ascii(unsigned char *src, unsigned char *src_end, unsigned char *desc, int
 #define RANGE_128      128
 #define RANGE_160      160
 
-
        if (enc == PG_LATIN1)
        {
                /*
@@ -64,9 +63,9 @@ pg_to_ascii(unsigned char *src, unsigned char *src_end, unsigned char *desc, int
        }
        else
        {
-               elog(ERROR, "pg_to_ascii(): unsupported encoding from %s",
+               elog(ERROR, "unsupported encoding conversion from %s to ASCII",
                         pg_encoding_to_char(enc));
-               return NULL;                    /* keep compiler quiet */
+               return;                                 /* keep compiler quiet */
        }
 
        /*
@@ -75,27 +74,27 @@ pg_to_ascii(unsigned char *src, unsigned char *src_end, unsigned char *desc, int
        for (x = src; x < src_end; x++)
        {
                if (*x < 128)
-                       *desc++ = *x;
+                       *dest++ = *x;
                else if (*x < range)
-                       *desc++ = ' ';          /* bogus 128 to 'range' */
+                       *dest++ = ' ';          /* bogus 128 to 'range' */
                else
-                       *desc++ = ascii[*x - range];
+                       *dest++ = ascii[*x - range];
        }
-
-       return desc;
 }
 
 /* ----------
  * encode text
+ *
+ * The text datum is overwritten in-place, therefore this coding method
+ * cannot support conversions that change the string length!
  * ----------
  */
 static text *
 encode_to_ascii(text *data, int enc)
 {
-       pg_to_ascii(
-                               (unsigned char *) VARDATA(data),                /* src */
-                               VARDATA(data) + VARSIZE(data),  /* src end */
-                               (unsigned char *) VARDATA(data),                /* desc */
+       pg_to_ascii((unsigned char *) VARDATA(data),            /* src */
+                               (unsigned char *) (data) + VARSIZE(data),       /* src end */
+                               (unsigned char *) VARDATA(data),                /* dest */
                                enc);                   /* encoding */
 
        return data;
@@ -108,14 +107,10 @@ encode_to_ascii(text *data, int enc)
 Datum
 to_ascii_encname(PG_FUNCTION_ARGS)
 {
-       PG_RETURN_TEXT_P
-               (
-                encode_to_ascii
-                (
-                 PG_GETARG_TEXT_P_COPY(0),
-                 pg_char_to_encoding(NameStr(*PG_GETARG_NAME(1)))
-                 )
-               );
+       text   *data = PG_GETARG_TEXT_P_COPY(0);
+       int             enc = pg_char_to_encoding(NameStr(*PG_GETARG_NAME(1)));
+
+       PG_RETURN_TEXT_P(encode_to_ascii(data, enc));
 }
 
 /* ----------
@@ -125,14 +120,10 @@ to_ascii_encname(PG_FUNCTION_ARGS)
 Datum
 to_ascii_enc(PG_FUNCTION_ARGS)
 {
-       PG_RETURN_TEXT_P
-               (
-                encode_to_ascii
-                (
-                 PG_GETARG_TEXT_P_COPY(0),
-                 PG_GETARG_INT32(1)
-                 )
-               );
+       text   *data = PG_GETARG_TEXT_P_COPY(0);
+       int             enc = PG_GETARG_INT32(1);
+
+       PG_RETURN_TEXT_P(encode_to_ascii(data, enc));
 }
 
 /* ----------
@@ -142,12 +133,8 @@ to_ascii_enc(PG_FUNCTION_ARGS)
 Datum
 to_ascii_default(PG_FUNCTION_ARGS)
 {
-       PG_RETURN_TEXT_P
-               (
-                encode_to_ascii
-                (
-                 PG_GETARG_TEXT_P_COPY(0),
-                 GetDatabaseEncoding()
-                 )
-               );
+       text   *data = PG_GETARG_TEXT_P_COPY(0);
+       int             enc = GetDatabaseEncoding();
+
+       PG_RETURN_TEXT_P(encode_to_ascii(data, enc));
 }