21 files changed, 442 insertions, 111 deletions

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index a86ba6089a4..2b34921e70b 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.222 2009/07/16 20:55:44 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.223 2009/08/04 16:08:35 tgl Exp $ -->
 
 <chapter Id="runtime-config">
   <title>Server Configuration</title>
@@ -4060,6 +4060,23 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-bytea-output" xreflabel="bytea_output">
+      <term><varname>bytea_output</varname> (<type>enum</type>)</term>
+      <indexterm>
+       <primary><varname>bytea_output</> configuration parameter</primary>
+      </indexterm>
+      <listitem>
+       <para>
+        Sets the output format for values of type <type>bytea</type>.
+        Valid values are <literal>hex</literal> (the default)
+        and <literal>escape</literal> (the traditional PostgreSQL
+        format).  See <xref linkend="datatype-binary"> for more
+        information.  The <type>bytea</type> type always
+        accepts both formats on input, regardless of this setting.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-xmlbinary" xreflabel="xmlbinary">
       <term><varname>xmlbinary</varname> (<type>enum</type>)</term>
       <indexterm>
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 774e4dbfb04..abe747a6964 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.240 2009/07/08 17:21:55 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.241 2009/08/04 16:08:35 tgl Exp $ -->
 
  <chapter id="datatype">
   <title id="datatype-title">Data Types</title>
@@ -1177,7 +1177,7 @@ SELECT b, char_length(b) FROM test2;
    <para>
     A binary string is a sequence of octets (or bytes).  Binary
     strings are distinguished from character strings in two
-    ways: First, binary strings specifically allow storing
+    ways.  First, binary strings specifically allow storing
     octets of value zero and other <quote>non-printable</quote>
     octets (usually, octets outside the range 32 to 126).
     Character strings disallow zero octets, and also disallow any
@@ -1191,13 +1191,82 @@ SELECT b, char_length(b) FROM test2;
    </para>
 
    <para>
-    When entering <type>bytea</type> values, octets of certain
-    values <emphasis>must</emphasis> be escaped (but all octet
-    values <emphasis>can</emphasis> be escaped) when used as part
-    of a string literal in an <acronym>SQL</acronym> statement. In
+    The <type>bytea</type> type supports two external formats for
+    input and output: <productname>PostgreSQL</productname>'s historical
+    <quote>escape</quote> format, and <quote>hex</quote> format.  Both
+    of these are always accepted on input.  The output format depends
+    on the configuration parameter <xref linkend="guc-bytea-output">;
+    the default is hex.  (Note that the hex format was introduced in
+    <productname>PostgreSQL</productname> 8.5; earlier versions and some
+    tools don't understand it.)
+   </para>
+
+   <para>
+    The <acronym>SQL</acronym> standard defines a different binary
+    string type, called <type>BLOB</type> or <type>BINARY LARGE
+    OBJECT</type>.  The input format is different from
+    <type>bytea</type>, but the provided functions and operators are
+    mostly the same.
+   </para>
+
+  <sect2>
+   <title><type>bytea</> hex format</title>
+
+   <para>
+    The <quote>hex</> format encodes binary data as 2 hexadecimal digits
+    per byte, most significant nibble first.  The entire string is
+    preceded by the sequence <literal>\x</literal> (to distinguish it
+    from the escape format).  In some contexts, the initial backslash may
+    need to be escaped by doubling it, in the same cases in which backslashes
+    have to be doubled in escape format; details appear below.
+    The hexadecimal digits can
+    be either upper or lower case, and whitespace is permitted between
+    digit pairs (but not within a digit pair nor in the starting
+    <literal>\x</literal> sequence).
+    The hex format is compatible with a wide
+    range of external applications and protocols, and it tends to be
+    faster to convert than the escape format, so its use is preferred.
+   </para>
+
+   <para>
+    Example:
+<programlisting>
+SELECT E'\\xDEADBEEF';
+</programlisting>
+   </para>
+  </sect2>
+
+  <sect2>
+   <title><type>bytea</> escape format</title>
+
+   <para>
+    The <quote>escape</quote> format is the traditional
+    <productname>PostgreSQL</productname> format for the <type>bytea</type>
+    type.  It
+    takes the approach of representing a binary string as a sequence
+    of ASCII characters, while converting those bytes that cannot be
+    represented as an ASCII character into special escape sequences.
+    If, from the point of view of the application, representing bytes
+    as characters makes sense, then this representation can be
+    convenient.  But in practice it is usually confusing becauses it
+    fuzzes up the distinction between binary strings and character
+    strings, and also the particular escape mechanism that was chosen is
+    somewhat unwieldy.  So this format should probably be avoided
+    for most new applications.
+   </para>
+
+   <para>
+    When entering <type>bytea</type> values in escape format,
+    octets of certain
+    values <emphasis>must</emphasis> be escaped, while all octet
+    values <emphasis>can</emphasis> be escaped.  In
     general, to escape an octet, convert it into its three-digit
     octal value and precede it
-    by two backslashes.  <xref linkend="datatype-binary-sqlesc">
+    by a backslash (or two backslashes, if writing the value as a
+    literal using escape string syntax).
+    Backslash itself (octet value 92) can alternatively be represented by
+    double backslashes.
+    <xref linkend="datatype-binary-sqlesc">
     shows the characters that must be escaped, and gives the alternative
     escape sequences where applicable.
    </para>
@@ -1343,14 +1412,7 @@ SELECT b, char_length(b) FROM test2;
     have to escape line feeds and carriage returns if your interface
     automatically translates these.
    </para>
-
-   <para>
-        The <acronym>SQL</acronym> standard defines a different binary
-        string type, called <type>BLOB</type> or <type>BINARY LARGE
-        OBJECT</type>.  The input format is different from
-        <type>bytea</type>, but the provided functions and operators are
-        mostly the same.
-   </para>
+  </sect2>
  </sect1>
 
 
diff --git a/src/backend/catalog/pg_largeobject.c b/src/backend/catalog/pg_largeobject.c
index 925d21387b8..313ccdd3f07 100644
--- a/src/backend/catalog/pg_largeobject.c
+++ b/src/backend/catalog/pg_largeobject.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/pg_largeobject.c,v 1.32 2009/01/01 17:23:37 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/pg_largeobject.c,v 1.33 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,7 +18,7 @@
 #include "access/heapam.h"
 #include "catalog/indexing.h"
 #include "catalog/pg_largeobject.h"
-#include "utils/builtins.h"
+#include "utils/bytea.h"
 #include "utils/fmgroids.h"
 #include "utils/rel.h"
 #include "utils/tqual.h"
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 7bc82127893..c1f55cfcf93 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.251 2009/07/30 02:45:36 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.252 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -37,6 +37,7 @@
 #include "tcop/utility.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
+#include "utils/bytea.h"
 #include "utils/fmgroids.h"
 #include "utils/inval.h"
 #include "utils/lsyscache.h"
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index b3f96eb773c..3930acf05a7 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.240 2009/06/11 14:48:58 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.241 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -31,6 +31,7 @@
 #include "optimizer/restrictinfo.h"
 #include "optimizer/var.h"
 #include "utils/builtins.h"
+#include "utils/bytea.h"
 #include "utils/lsyscache.h"
 #include "utils/pg_locale.h"
 #include "utils/selfuncs.h"
diff --git a/src/backend/utils/adt/encode.c b/src/backend/utils/adt/encode.c
index 480b85cefcb..e581e3bc42d 100644
--- a/src/backend/utils/adt/encode.c
+++ b/src/backend/utils/adt/encode.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/encode.c,v 1.23 2009/01/01 17:23:49 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/encode.c,v 1.24 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -109,7 +109,7 @@ binary_decode(PG_FUNCTION_ARGS)
  * HEX
  */
 
-static const char *hextbl = "0123456789abcdef";
+static const char hextbl[] = "0123456789abcdef";
 
 static const int8 hexlookup[128] = {
 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
@@ -122,7 +122,7 @@ static const int8 hexlookup[128] = {
 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 };
 
-static unsigned
+unsigned
 hex_encode(const char *src, unsigned len, char *dst)
 {
 	const char *end = src + len;
@@ -136,7 +136,7 @@ hex_encode(const char *src, unsigned len, char *dst)
 	return len * 2;
 }
 
-static char
+static inline char
 get_hex(char c)
 {
 	int			res = -1;
@@ -152,7 +152,7 @@ get_hex(char c)
 	return (char) res;
 }
 
-static unsigned
+unsigned
 hex_decode(const char *src, unsigned len, char *dst)
 {
 	const char *s,
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 3d60885a795..e85ab06819c 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.261 2009/06/11 14:49:04 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.262 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -109,6 +109,7 @@
 #include "parser/parse_coerce.h"
 #include "parser/parsetree.h"
 #include "utils/builtins.h"
+#include "utils/bytea.h"
 #include "utils/date.h"
 #include "utils/datum.h"
 #include "utils/fmgroids.h"
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index b9b54e6db63..c524454432e 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.171 2009/06/11 14:49:04 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.172 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -24,10 +24,14 @@
 #include "parser/scansup.h"
 #include "regex/regex.h"
 #include "utils/builtins.h"
+#include "utils/bytea.h"
 #include "utils/lsyscache.h"
 #include "utils/pg_locale.h"
 
 
+/* GUC variable */
+int		bytea_output = BYTEA_OUTPUT_HEX;
+
 typedef struct varlena unknown;
 
 typedef struct
@@ -186,10 +190,24 @@ byteain(PG_FUNCTION_ARGS)
 	char	   *inputText = PG_GETARG_CSTRING(0);
 	char	   *tp;
 	char	   *rp;
-	int byte;
+	int			bc;
 	bytea	   *result;
 
-	for (byte = 0, tp = inputText; *tp != '\0'; byte ++)
+	/* Recognize hex input */
+	if (inputText[0] == '\\' && inputText[1] == 'x')
+	{
+		size_t len = strlen(inputText);
+
+		bc = (len - 2)/2 + VARHDRSZ;		/* maximum possible length */
+		result = palloc(bc);
+		bc = hex_decode(inputText + 2, len - 2, VARDATA(result));
+		SET_VARSIZE(result, bc + VARHDRSZ);	/* actual length */
+
+		PG_RETURN_BYTEA_P(result);
+	}
+
+	/* Else, it's the traditional escaped style */
+	for (bc = 0, tp = inputText; *tp != '\0'; bc++)
 	{
 		if (tp[0] != '\\')
 			tp++;
@@ -204,7 +222,7 @@ byteain(PG_FUNCTION_ARGS)
 		else
 		{
 			/*
-			 * one backslash, not followed by 0 or ### valid octal
+			 * one backslash, not followed by another or ### valid octal
 			 */
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
@@ -212,10 +230,10 @@ byteain(PG_FUNCTION_ARGS)
 		}
 	}
 
-	byte	  +=VARHDRSZ;
+	bc += VARHDRSZ;
 
-	result = (bytea *) palloc(byte);
-	SET_VARSIZE(result, byte);
+	result = (bytea *) palloc(bc);
+	SET_VARSIZE(result, bc);
 
 	tp = inputText;
 	rp = VARDATA(result);
@@ -228,11 +246,11 @@ byteain(PG_FUNCTION_ARGS)
 				 (tp[2] >= '0' && tp[2] <= '7') &&
 				 (tp[3] >= '0' && tp[3] <= '7'))
 		{
-			byte = VAL(tp[1]);
-			byte	 <<=3;
-			byte	  +=VAL(tp[2]);
-			byte	 <<=3;
-			*rp++ = byte +VAL(tp[3]);
+			bc = VAL(tp[1]);
+			bc <<= 3;
+			bc += VAL(tp[2]);
+			bc <<= 3;
+			*rp++ = bc + VAL(tp[3]);
 
 			tp += 4;
 		}
@@ -259,21 +277,30 @@ byteain(PG_FUNCTION_ARGS)
 /*
  *		byteaout		- converts to printable representation of byte array
  *
- *		Non-printable characters are inserted as '\nnn' (octal) and '\' as
- *		'\\'.
- *
- *		NULL vlena should be an error--returning string with NULL for now.
+ *		In the traditional escaped format, non-printable characters are
+ *		printed as '\nnn' (octal) and '\' as '\\'.
  */
 Datum
 byteaout(PG_FUNCTION_ARGS)
 {
 	bytea	   *vlena = PG_GETARG_BYTEA_PP(0);
 	char	   *result;
-	char	   *vp;
 	char	   *rp;
-	int			val;			/* holds unprintable chars */
-	int			i;
+
+	if (bytea_output == BYTEA_OUTPUT_HEX)
+	{
+		/* Print hex format */
+		rp = result = palloc(VARSIZE_ANY_EXHDR(vlena) * 2 + 2 + 1);
+		*rp++ = '\\';
+		*rp++ = 'x';
+		rp += hex_encode(VARDATA_ANY(vlena), VARSIZE_ANY_EXHDR(vlena), rp);
+	}
+	else if (bytea_output == BYTEA_OUTPUT_ESCAPE)
+	{
+	/* Print traditional escaped format */
+	char	   *vp;
 	int			len;
+	int			i;
 
 	len = 1;					/* empty string has 1 char */
 	vp = VARDATA_ANY(vlena);
@@ -297,6 +324,8 @@ byteaout(PG_FUNCTION_ARGS)
 		}
 		else if ((unsigned char) *vp < 0x20 || (unsigned char) *vp > 0x7e)
 		{
+			int			val;			/* holds unprintable chars */
+
 			val = *vp;
 			rp[0] = '\\';
 			rp[3] = DIG(val & 07);
@@ -309,6 +338,13 @@ byteaout(PG_FUNCTION_ARGS)
 		else
 			*rp++ = *vp;
 	}
+	}
+	else
+	{
+		elog(ERROR, "unrecognized bytea_output setting: %d",
+			 bytea_output);
+		rp = result = NULL;		/* keep compiler quiet */
+	}
 	*rp = '\0';
 	PG_RETURN_CSTRING(result);
 }
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 76d3ec9da65..264b45451a9 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.509 2009/07/22 17:00:23 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.510 2009/08/04 16:08:36 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -61,6 +61,7 @@
 #include "tcop/tcopprot.h"
 #include "tsearch/ts_cache.h"
 #include "utils/builtins.h"
+#include "utils/bytea.h"
 #include "utils/guc_tables.h"
 #include "utils/memutils.h"
 #include "utils/pg_locale.h"
@@ -180,6 +181,12 @@ static char *config_enum_get_options(struct config_enum * record,
  * NOTE! Option values may not contain double quotes!
  */
 
+static const struct config_enum_entry bytea_output_options[] = {
+	{"escape", BYTEA_OUTPUT_ESCAPE, false},
+	{"hex", BYTEA_OUTPUT_HEX, false},
+	{NULL, 0, false}
+};
+
 /*
  * We have different sets for client and server message level options because
  * they sort slightly different (see "log" level)
@@ -2541,6 +2548,15 @@ static struct config_enum ConfigureNamesEnum[] =
 	},
 
 	{
+		{"bytea_output", PGC_USERSET, CLIENT_CONN_STATEMENT,
+			gettext_noop("Sets the output format for bytea."),
+			NULL
+		},
+		&bytea_output,
+		BYTEA_OUTPUT_HEX, bytea_output_options, NULL, NULL
+	},
+
+	{
 		{"client_min_messages", PGC_USERSET, LOGGING_WHEN,
 			gettext_noop("Sets the message levels that are sent to the client."),
 			gettext_noop("Each level includes all the levels that follow it. The later"
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index e50d7a44f7b..41488e264f0 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -424,6 +424,7 @@
 #statement_timeout = 0			# in milliseconds, 0 is disabled
 #vacuum_freeze_min_age = 50000000
 #vacuum_freeze_table_age = 150000000
+#bytea_output = 'hex'			# hex, escape
 #xmlbinary = 'base64'
 #xmloption = 'content'
 
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 360eaf1caf7..b46c068d4ec 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -12,7 +12,7 @@
  *	by PostgreSQL
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.544 2009/08/02 22:14:52 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.545 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -11008,6 +11008,8 @@ dumpTrigger(Archive *fout, TriggerInfo *tginfo)
 	TableInfo  *tbinfo = tginfo->tgtable;
 	PQExpBuffer query;
 	PQExpBuffer delqry;
+	char	   *tgargs;
+	size_t		lentgargs;
 	const char *p;
 	int			findx;
 
@@ -11109,53 +11111,29 @@ dumpTrigger(Archive *fout, TriggerInfo *tginfo)
 		appendPQExpBuffer(query, "EXECUTE PROCEDURE %s(",
 						  fmtId(tginfo->tgfname));
 
-	p = tginfo->tgargs;
+	tgargs = (char *) PQunescapeBytea(tginfo->tgargs, &lentgargs);
+	p = tgargs;
 	for (findx = 0; findx < tginfo->tgnargs; findx++)
 	{
-		const char *s = p;
+		/* find the embedded null that terminates this trigger argument */
+		size_t	tlen = strlen(p);
 
-		/* Set 'p' to end of arg string. marked by '\000' */
-		for (;;)
+		if (p + tlen >= tgargs + lentgargs)
 		{
-			p = strchr(p, '\\');
-			if (p == NULL)
-			{
-				write_msg(NULL, "invalid argument string (%s) for trigger \"%s\" on table \"%s\"\n",
-						  tginfo->tgargs,
-						  tginfo->dobj.name,
-						  tbinfo->dobj.name);
-				exit_nicely();
-			}
-			p++;
-			if (*p == '\\')		/* is it '\\'? */
-			{
-				p++;
-				continue;
-			}
-			if (p[0] == '0' && p[1] == '0' && p[2] == '0')		/* is it '\000'? */
-				break;
+			/* hm, not found before end of bytea value... */
+			write_msg(NULL, "invalid argument string (%s) for trigger \"%s\" on table \"%s\"\n",
+					  tginfo->tgargs,
+					  tginfo->dobj.name,
+					  tbinfo->dobj.name);
+			exit_nicely();
 		}
-		p--;
-
-		appendPQExpBufferChar(query, '\'');
-		while (s < p)
-		{
-			if (*s == '\'')
-				appendPQExpBufferChar(query, '\'');
 
-			/*
-			 * bytea unconditionally doubles backslashes, so we suppress the
-			 * doubling for standard_conforming_strings.
-			 */
-			if (fout->std_strings && *s == '\\' && s[1] == '\\')
-				s++;
-			appendPQExpBufferChar(query, *s++);
-		}
-		appendPQExpBufferChar(query, '\'');
-		appendPQExpBuffer(query,
-						  (findx < tginfo->tgnargs - 1) ? ", " : "");
-		p = p + 4;
+		if (findx > 0)
+			appendPQExpBuffer(query, ", ");
+		appendStringLiteralAH(query, p, fout);
+		p += tlen + 1;
 	}
+	free(tgargs);
 	appendPQExpBuffer(query, ");\n");
 
 	if (tginfo->tgenabled != 't' && tginfo->tgenabled != 'O')
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 4b92cbcb608..b664799fc47 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.337 2009/08/03 21:11:39 joe Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.338 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -138,6 +138,12 @@ extern Datum char_text(PG_FUNCTION_ARGS);
 extern Datum domain_in(PG_FUNCTION_ARGS);
 extern Datum domain_recv(PG_FUNCTION_ARGS);
 
+/* encode.c */
+extern Datum binary_encode(PG_FUNCTION_ARGS);
+extern Datum binary_decode(PG_FUNCTION_ARGS);
+extern unsigned hex_encode(const char *src, unsigned len, char *dst);
+extern unsigned hex_decode(const char *src, unsigned len, char *dst);
+
 /* enum.c */
 extern Datum enum_in(PG_FUNCTION_ARGS);
 extern Datum enum_out(PG_FUNCTION_ARGS);
@@ -711,28 +717,6 @@ extern Datum unknownout(PG_FUNCTION_ARGS);
 extern Datum unknownrecv(PG_FUNCTION_ARGS);
 extern Datum unknownsend(PG_FUNCTION_ARGS);
 
-extern Datum byteain(PG_FUNCTION_ARGS);
-extern Datum byteaout(PG_FUNCTION_ARGS);
-extern Datum bytearecv(PG_FUNCTION_ARGS);
-extern Datum byteasend(PG_FUNCTION_ARGS);
-extern Datum byteaoctetlen(PG_FUNCTION_ARGS);
-extern Datum byteaGetByte(PG_FUNCTION_ARGS);
-extern Datum byteaGetBit(PG_FUNCTION_ARGS);
-extern Datum byteaSetByte(PG_FUNCTION_ARGS);
-extern Datum byteaSetBit(PG_FUNCTION_ARGS);
-extern Datum binary_encode(PG_FUNCTION_ARGS);
-extern Datum binary_decode(PG_FUNCTION_ARGS);
-extern Datum byteaeq(PG_FUNCTION_ARGS);
-extern Datum byteane(PG_FUNCTION_ARGS);
-extern Datum bytealt(PG_FUNCTION_ARGS);
-extern Datum byteale(PG_FUNCTION_ARGS);
-extern Datum byteagt(PG_FUNCTION_ARGS);
-extern Datum byteage(PG_FUNCTION_ARGS);
-extern Datum byteacmp(PG_FUNCTION_ARGS);
-extern Datum byteacat(PG_FUNCTION_ARGS);
-extern Datum byteapos(PG_FUNCTION_ARGS);
-extern Datum bytea_substr(PG_FUNCTION_ARGS);
-extern Datum bytea_substr_no_len(PG_FUNCTION_ARGS);
 extern Datum pg_column_size(PG_FUNCTION_ARGS);
 
 /* version.c */
diff --git a/src/include/utils/bytea.h b/src/include/utils/bytea.h
new file mode 100644
index 00000000000..8750d6d0e9c
--- /dev/null
+++ b/src/include/utils/bytea.h
@@ -0,0 +1,50 @@
+/*-------------------------------------------------------------------------
+ *
+ * bytea.h
+ *	  Declarations for BYTEA data type support.
+ *
+ *
+ * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/include/utils/bytea.h,v 1.1 2009/08/04 16:08:36 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef BYTEA_H
+#define BYTEA_H
+
+#include "fmgr.h"
+
+
+typedef enum
+{
+	BYTEA_OUTPUT_ESCAPE,
+	BYTEA_OUTPUT_HEX
+} ByteaOutputType;
+
+extern int	bytea_output;		/* ByteaOutputType, but int for GUC enum */
+
+/* functions are in utils/adt/varlena.c */
+extern Datum byteain(PG_FUNCTION_ARGS);
+extern Datum byteaout(PG_FUNCTION_ARGS);
+extern Datum bytearecv(PG_FUNCTION_ARGS);
+extern Datum byteasend(PG_FUNCTION_ARGS);
+extern Datum byteaoctetlen(PG_FUNCTION_ARGS);
+extern Datum byteaGetByte(PG_FUNCTION_ARGS);
+extern Datum byteaGetBit(PG_FUNCTION_ARGS);
+extern Datum byteaSetByte(PG_FUNCTION_ARGS);
+extern Datum byteaSetBit(PG_FUNCTION_ARGS);
+extern Datum byteaeq(PG_FUNCTION_ARGS);
+extern Datum byteane(PG_FUNCTION_ARGS);
+extern Datum bytealt(PG_FUNCTION_ARGS);
+extern Datum byteale(PG_FUNCTION_ARGS);
+extern Datum byteagt(PG_FUNCTION_ARGS);
+extern Datum byteage(PG_FUNCTION_ARGS);
+extern Datum byteacmp(PG_FUNCTION_ARGS);
+extern Datum byteacat(PG_FUNCTION_ARGS);
+extern Datum byteapos(PG_FUNCTION_ARGS);
+extern Datum bytea_substr(PG_FUNCTION_ARGS);
+extern Datum bytea_substr_no_len(PG_FUNCTION_ARGS);
+
+#endif   /* BYTEA_H */
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index c00f5eae6ab..f1318a4a942 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.203 2009/06/11 14:49:13 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.204 2009/08/04 16:08:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3167,6 +3167,29 @@ PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
 }
 
 
+static const int8 hexlookup[128] = {
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
+	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+};
+
+static inline char
+get_hex(char c)
+{
+	int			res = -1;
+
+	if (c > 0 && c < 127)
+		res = hexlookup[(unsigned char) c];
+
+	return (char) res;
+}
+
+
 #define ISFIRSTOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '3')
 #define ISOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '7')
 #define OCTVAL(CH) ((CH) - '0')
@@ -3198,6 +3221,40 @@ PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
 
 	strtextlen = strlen((const char *) strtext);
 
+	if (strtext[0] == '\\' && strtext[1] == 'x')
+	{
+		const unsigned char *s;
+		unsigned char	*p;
+
+		buflen = (strtextlen - 2)/2;
+		/* Avoid unportable malloc(0) */
+		buffer = (unsigned char *) malloc(buflen > 0 ? buflen : 1);
+		if (buffer == NULL)
+			return NULL;
+
+		s = strtext + 2;
+		p = buffer;
+		while (*s)
+		{
+			char	v1,
+					v2;
+
+			/*
+			 * Bad input is silently ignored.  Note that this includes
+			 * whitespace between hex pairs, which is allowed by byteain.
+			 */
+			v1 = get_hex(*s++);
+			if (!*s || v1 == (char) -1)
+				continue;
+			v2 = get_hex(*s++);
+			if (v2 != (char) -1)
+				*p++ = (v1 << 4) | v2;
+		}
+
+		buflen = p - buffer;
+	}
+	else
+	{
 	/*
 	 * Length of input is max length of output, but add one to avoid
 	 * unportable malloc(0) if input is zero-length.
@@ -3244,6 +3301,7 @@ PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
 		}
 	}
 	buflen = j;					/* buflen is the length of the dequoted data */
+	}
 
 	/* Shrink the buffer to be no larger than necessary */
 	/* +1 avoids unportable behavior when buflen==0 */
diff --git a/src/test/regress/expected/conversion.out b/src/test/regress/expected/conversion.out
index e80e1a45343..82eca262f09 100644
--- a/src/test/regress/expected/conversion.out
+++ b/src/test/regress/expected/conversion.out
@@ -1,3 +1,5 @@
+-- ensure consistent test output regardless of the default bytea format
+SET bytea_output TO escape;
 --
 -- create user defined conversion
 --
diff --git a/src/test/regress/expected/strings.out b/src/test/regress/expected/strings.out
index 1241a2ace63..392f48ef8c6 100644
--- a/src/test/regress/expected/strings.out
+++ b/src/test/regress/expected/strings.out
@@ -97,6 +97,99 @@ LINE 1: SELECT U&'wrong: +0061' UESCAPE '+';
                ^
 DETAIL:  String constants with Unicode escapes cannot be used when standard_conforming_strings is off.
 RESET standard_conforming_strings;
+-- bytea
+SET bytea_output TO hex;
+SELECT E'\\xDeAdBeEf'::bytea;
+   bytea    
+------------
+ \xdeadbeef
+(1 row)
+
+SELECT E'\\x De Ad Be Ef '::bytea;
+   bytea    
+------------
+ \xdeadbeef
+(1 row)
+
+SELECT E'\\xDeAdBeE'::bytea;
+ERROR:  invalid hexadecimal data: odd number of digits
+LINE 1: SELECT E'\\xDeAdBeE'::bytea;
+               ^
+SELECT E'\\xDeAdBeEx'::bytea;
+ERROR:  invalid hexadecimal digit: "x"
+LINE 1: SELECT E'\\xDeAdBeEx'::bytea;
+               ^
+SELECT E'\\xDe00BeEf'::bytea;
+   bytea    
+------------
+ \xde00beef
+(1 row)
+
+SELECT E'DeAdBeEf'::bytea;
+       bytea        
+--------------------
+ \x4465416442654566
+(1 row)
+
+SELECT E'De\\000dBeEf'::bytea;
+       bytea        
+--------------------
+ \x4465006442654566
+(1 row)
+
+SELECT E'De\123dBeEf'::bytea;
+       bytea        
+--------------------
+ \x4465536442654566
+(1 row)
+
+SELECT E'De\\123dBeEf'::bytea;
+       bytea        
+--------------------
+ \x4465536442654566
+(1 row)
+
+SELECT E'De\\678dBeEf'::bytea;
+ERROR:  invalid input syntax for type bytea
+LINE 1: SELECT E'De\\678dBeEf'::bytea;
+               ^
+SET bytea_output TO escape;
+SELECT E'\\xDeAdBeEf'::bytea;
+      bytea       
+------------------
+ \336\255\276\357
+(1 row)
+
+SELECT E'\\x De Ad Be Ef '::bytea;
+      bytea       
+------------------
+ \336\255\276\357
+(1 row)
+
+SELECT E'\\xDe00BeEf'::bytea;
+      bytea       
+------------------
+ \336\000\276\357
+(1 row)
+
+SELECT E'DeAdBeEf'::bytea;
+  bytea   
+----------
+ DeAdBeEf
+(1 row)
+
+SELECT E'De\\000dBeEf'::bytea;
+    bytea    
+-------------
+ De\000dBeEf
+(1 row)
+
+SELECT E'De\\123dBeEf'::bytea;
+  bytea   
+----------
+ DeSdBeEf
+(1 row)
+
 --
 -- test conversions between various string types
 -- E021-10 implicit casting among the character data types
diff --git a/src/test/regress/input/largeobject.source b/src/test/regress/input/largeobject.source
index 46ba9261ac5..807cfd7cc46 100644
--- a/src/test/regress/input/largeobject.source
+++ b/src/test/regress/input/largeobject.source
@@ -2,6 +2,9 @@
 -- Test large object support
 --
 
+-- ensure consistent test output regardless of the default bytea format
+SET bytea_output TO escape;
+
 -- Load a file
 CREATE TABLE lotest_stash_values (loid oid, fd integer);
 -- lo_creat(mode integer) returns oid
diff --git a/src/test/regress/output/largeobject.source b/src/test/regress/output/largeobject.source
index 9d69f6c913e..d7468bb5131 100644
--- a/src/test/regress/output/largeobject.source
+++ b/src/test/regress/output/largeobject.source
@@ -1,6 +1,8 @@
 --
 -- Test large object support
 --
+-- ensure consistent test output regardless of the default bytea format
+SET bytea_output TO escape;
 -- Load a file
 CREATE TABLE lotest_stash_values (loid oid, fd integer);
 -- lo_creat(mode integer) returns oid
diff --git a/src/test/regress/output/largeobject_1.source b/src/test/regress/output/largeobject_1.source
index 1fbc29c2517..84e916fea45 100644
--- a/src/test/regress/output/largeobject_1.source
+++ b/src/test/regress/output/largeobject_1.source
@@ -1,6 +1,8 @@
 --
 -- Test large object support
 --
+-- ensure consistent test output regardless of the default bytea format
+SET bytea_output TO escape;
 -- Load a file
 CREATE TABLE lotest_stash_values (loid oid, fd integer);
 -- lo_creat(mode integer) returns oid
diff --git a/src/test/regress/sql/conversion.sql b/src/test/regress/sql/conversion.sql
index 99a9178315e..be194eec1f1 100644
--- a/src/test/regress/sql/conversion.sql
+++ b/src/test/regress/sql/conversion.sql
@@ -1,3 +1,6 @@
+-- ensure consistent test output regardless of the default bytea format
+SET bytea_output TO escape;
+
 --
 -- create user defined conversion
 --
diff --git a/src/test/regress/sql/strings.sql b/src/test/regress/sql/strings.sql
index 681a0e1e62c..63df9402ed7 100644
--- a/src/test/regress/sql/strings.sql
+++ b/src/test/regress/sql/strings.sql
@@ -43,6 +43,27 @@ SELECT U&'wrong: +0061' UESCAPE '+';
 
 RESET standard_conforming_strings;
 
+-- bytea
+SET bytea_output TO hex;
+SELECT E'\\xDeAdBeEf'::bytea;
+SELECT E'\\x De Ad Be Ef '::bytea;
+SELECT E'\\xDeAdBeE'::bytea;
+SELECT E'\\xDeAdBeEx'::bytea;
+SELECT E'\\xDe00BeEf'::bytea;
+SELECT E'DeAdBeEf'::bytea;
+SELECT E'De\\000dBeEf'::bytea;
+SELECT E'De\123dBeEf'::bytea;
+SELECT E'De\\123dBeEf'::bytea;
+SELECT E'De\\678dBeEf'::bytea;
+
+SET bytea_output TO escape;
+SELECT E'\\xDeAdBeEf'::bytea;
+SELECT E'\\x De Ad Be Ef '::bytea;
+SELECT E'\\xDe00BeEf'::bytea;
+SELECT E'DeAdBeEf'::bytea;
+SELECT E'De\\000dBeEf'::bytea;
+SELECT E'De\\123dBeEf'::bytea;
+
 --
 -- test conversions between various string types
 -- E021-10 implicit casting among the character data types