> Here's a revised patch. Changes:

>
> 1. Now outputs '\\' instead of '\134' when using encode(bytea, 'escape')
> Note that I ended up leaving \0 as \000 so that there are no ambiguities
> when decoding something like, for example, \0123.
>
> 2. Fixed bug in byteain which allowed input values which were not valid
> octals (e.g. \789), to be parsed as if they were octals.
>
> Joe
>

Here's rev 2 of the bytea string support patch. Changes:

1. Added missing declaration for MatchBytea function
2. Added PQescapeBytea to fe-exec.c
3. Applies cleanly on cvs tip from this afternoon

I'm hoping that someone can review/approve/apply this before beta starts, so
I guess I'd vote (not that it counts for much) to delay beta a few days :-)

Joe Conway

1 files changed, 73 insertions, 1 deletions

diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index e7495dabf7f..2741ec67aa6 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.111 2001/09/13 17:00:34 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.112 2001/09/14 17:46:40 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -104,7 +104,79 @@ PQescapeString (char *to, const char *from, size_t length)
 	return target - to;
 }
 
+/*
+ *		PQescapeBytea	- converts from binary string to the
+ *		minimal encoding necessary to include the string in an SQL
+ *		INSERT statement with a bytea type column as the target.
+ *
+ *		The following transformations are applied
+ *		'\0' == ASCII  0 == \\000
+ *		'\'' == ASCII 39 == \'
+ *		'\\' == ASCII 92 == \\\\
+ */
+unsigned char *
+PQescapeBytea(unsigned char *bintext, size_t binlen, size_t *bytealen)
+{
+	unsigned char	   *vp;
+	unsigned char	   *rp;
+	unsigned char	   *result;
+	size_t				i;
+	size_t				len;
+
+	/*
+	 * empty string has 1 char ('\0')
+	 */
+	len = 1;
+
+	vp = bintext;
+	for (i = binlen; i != 0; i--, vp++)
+	{
+		if (*vp == 0)
+			len += 5;
+		else if (*vp == 39)
+			len += 2;
+		else if (*vp == 92)
+			len += 4;
+		else
+			len++;
+	}
+
+	rp = result = (unsigned char *) malloc(len);
+	vp = bintext;
+	*bytealen = len;
 
+	for (i = binlen; i != 0; i--, vp++)
+	{
+		if (*vp == 0)
+		{
+			rp[0] = '\\';
+			rp[1] = '\\';
+			rp[2] = '0';
+			rp[3] = '0';
+			rp[4] = '0';
+			rp += 5;
+		}
+		else if (*vp == 39)
+		{
+			rp[0] = '\\';
+			rp[1] = '\'';
+			rp += 2;
+		}
+		else if (*vp == 92)
+		{
+			rp[0] = '\\';
+			rp[1] = '\\';
+			rp[2] = '\\';
+			rp[3] = '\\';
+			rp += 4;
+		}
+		else
+			*rp++ = *vp;
+	}
+	*rp = '\0';
+
+	return result;
+}
 
 /* ----------------
  * Space management for PGresult.