From fa98a86f65cc2d71cbef5caa063f12c66233238c Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 28 May 2007 16:43:24 +0000
Subject: [PATCH] Tweak the code in a couple of places to try to deliver more
user-friendly error messages when a single COPY line is too long for us to
handle. Per example from Johann Spies.
---
src/backend/lib/stringinfo.c | 19 ++++++++------
src/backend/utils/mb/mbutils.c | 48 +++++++++++++++++++++++++++-------
2 files changed, 50 insertions(+), 17 deletions(-)
diff --git a/src/backend/lib/stringinfo.c b/src/backend/lib/stringinfo.c
index b0854ddc43b..a35f30b933b 100644
--- a/src/backend/lib/stringinfo.c
+++ b/src/backend/lib/stringinfo.c
@@ -9,7 +9,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/lib/stringinfo.c,v 1.45 2007/03/03 19:32:54 neilc Exp $
+ * $PostgreSQL: pgsql/src/backend/lib/stringinfo.c,v 1.46 2007/05/28 16:43:24 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -234,14 +234,17 @@ enlargeStringInfo(StringInfo str, int needed)
int newlen;
/*
- * Guard against ridiculous "needed" values, which can occur if we're fed
- * bogus data. Without this, we can get an overflow or infinite loop in
- * the following.
+ * Guard against out-of-range "needed" values. Without this, we can get
+ * an overflow or infinite loop in the following.
*/
- if (needed < 0 ||
- ((Size) needed) >= (MaxAllocSize - (Size) str->len))
- elog(ERROR, "invalid string enlargement request size %d",
- needed);
+ if (needed < 0) /* should not happen */
+ elog(ERROR, "invalid string enlargement request size: %d", needed);
+ if (((Size) needed) >= (MaxAllocSize - (Size) str->len))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("out of memory"),
+ errdetail("Cannot enlarge string buffer containing %d bytes by %d more bytes.",
+ str->len, needed)));
needed += str->len + 1; /* total space required now */
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
index cee6807d66c..a466073ca0a 100644
--- a/src/backend/utils/mb/mbutils.c
+++ b/src/backend/utils/mb/mbutils.c
@@ -4,7 +4,7 @@
* (currently mule internal code (mic) is used)
* Tatsuo Ishii
*
- * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.62 2007/02/27 23:48:09 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.63 2007/05/28 16:43:24 tgl Exp $
*/
#include "postgres.h"
@@ -15,6 +15,17 @@
#include "utils/memutils.h"
#include "utils/syscache.h"
+/*
+ * When converting strings between different encodings, we assume that space
+ * for converted result is 4-to-1 growth in the worst case. The rate for
+ * currently supported encoding pairs are within 3 (SJIS JIS X0201 half width
+ * kanna -> UTF8 is the worst case). So "4" should be enough for the moment.
+ *
+ * Note that this is not the same as the maximum character width in any
+ * particular encoding.
+ */
+#define MAX_CONVERSION_GROWTH 4
+
/*
* We handle for actual FE and BE encoding setting encoding-identificator
* and encoding-name too. It prevent searching and conversion from encoding
@@ -207,15 +218,14 @@ pg_get_client_encoding_name(void)
* conversion function is chosen from the pg_conversion system catalog
* marked as "default". If it is not found in the schema search path,
* it's taken from pg_catalog schema. If it even is not in the schema,
- * warn and returns src. We cannot raise an error, since it will cause
- * an infinit loop in error message sending.
+ * warn and return src.
*
* In the case of no conversion, src is returned.
*
- * XXX We assume that storage for converted result is 4-to-1 growth in
- * the worst case. The rate for currently supported encoding pares are within 3
- * (SJIS JIS X0201 half width kanna -> UTF8 is the worst case).
- * So "4" should be enough for the moment.
+ * Note: we try to avoid raising error, since that could get us into
+ * infinite recursion when this function is invoked during error message
+ * sending. It should be OK to raise error for overlength strings though,
+ * since the recursion will come with a shorter message.
*/
unsigned char *
pg_do_encoding_conversion(unsigned char *src, int len,
@@ -260,7 +270,17 @@ pg_do_encoding_conversion(unsigned char *src, int len,
return src;
}
- result = palloc(len * 4 + 1);
+ /*
+ * Allocate space for conversion result, being wary of integer overflow
+ */
+ if ((Size) len >= (MaxAllocSize / (Size) MAX_CONVERSION_GROWTH))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("out of memory"),
+ errdetail("String of %d bytes is too long for encoding conversion.",
+ len)));
+
+ result = palloc(len * MAX_CONVERSION_GROWTH + 1);
OidFunctionCall5(proc,
Int32GetDatum(src_encoding),
@@ -458,7 +478,17 @@ perform_default_encoding_conversion(const char *src, int len, bool is_client_to_
if (flinfo == NULL)
return (char *) src;
- result = palloc(len * 4 + 1);
+ /*
+ * Allocate space for conversion result, being wary of integer overflow
+ */
+ if ((Size) len >= (MaxAllocSize / (Size) MAX_CONVERSION_GROWTH))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("out of memory"),
+ errdetail("String of %d bytes is too long for encoding conversion.",
+ len)));
+
+ result = palloc(len * MAX_CONVERSION_GROWTH + 1);
FunctionCall5(flinfo,
Int32GetDatum(src_encoding),
--
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