BLOBs containing NUL characters (ASCII 0) can be written to the

bmomjian · bmomjian · commit 7ee7ee1398ac · 1999-10-13T02:26:37.000Z
database, but they get truncated at the first NUL by lo_read
when they are read back. The reason for this is that lo_read in
Pg.xs is using the default:
    OUTPUT:
        RETVAL
        buf
which uses C's strlen() to work out the length of the scalar.

The code ought to read something more like:
    OUTPUT:
        RETVAL
        buf sv_setpvn((SV*)ST(2), buf, RETVAL);

I am not sure if this needs to be done on both lo_read methods
in this file, but I changed both and have not since had any
problems with truncated BLOBs.

Douglas Thomson &lt;dougt@mugc.cc.monash.edu.au&gt;
diff --git a/src/interfaces/perl5/Pg.xs b/src/interfaces/perl5/Pg.xs
@@ -1,6 +1,6 @@
 /*-------------------------------------------------------
  *
- * $Id: Pg.xs,v 1.12 1999/02/19 23:27:17 tgl Exp $
+ * $Id: Pg.xs,v 1.13 1999/10/13 02:26:37 momjian Exp $ with patch for NULs
  *
  * Copyright (c) 1997, 1998  Edmund Mergl
  *
@@ -643,7 +643,7 @@ lo_read(conn, fd, buf, len)
 		}
 	OUTPUT:
 		RETVAL
-		buf
+		buf sv_setpvn((SV*)ST(2), buf, RETVAL);   /* to handle NULs */
 
 int
 lo_write(conn, fd, buf, len)
@@ -1029,7 +1029,7 @@ lo_read(conn, fd, buf, len)
 		}
 	OUTPUT:
 		RETVAL
-		buf
+		buf sv_setpvn((SV*)ST(2), buf, RETVAL);   /* to handle NULs */
 
 
 int

Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`/*-------------------------------------------------------`
`2`	`2`	`*`
`3`		`- * $Id: Pg.xs,v 1.12 1999/02/19 23:27:17 tgl Exp $`
	`3`	`+ * $Id: Pg.xs,v 1.13 1999/10/13 02:26:37 momjian Exp $ with patch for NULs`
`4`	`4`	`*`
`5`	`5`	`* Copyright (c) 1997, 1998 Edmund Mergl`
`6`	`6`	`*`
`@@ -643,7 +643,7 @@ lo_read(conn, fd, buf, len)`
`643`	`643`	`}`
`644`	`644`	`OUTPUT:`
`645`	`645`	`RETVAL`
`646`		`- buf`
	`646`	`+ buf sv_setpvn((SV)ST(2), buf, RETVAL); / to handle NULs */`
`647`	`647`
`648`	`648`	`int`
`649`	`649`	`lo_write(conn, fd, buf, len)`
`@@ -1029,7 +1029,7 @@ lo_read(conn, fd, buf, len)`
`1029`	`1029`	`}`
`1030`	`1030`	`OUTPUT:`
`1031`	`1031`	`RETVAL`
`1032`		`- buf`
	`1032`	`+ buf sv_setpvn((SV)ST(2), buf, RETVAL); / to handle NULs */`
`1033`	`1033`
`1034`	`1034`
`1035`	`1035`	`int`