Update libpq to store an error message in PGresult, per pgsq-interfaces discussion of 21-Sep.

src/interfaces/libpq/fe-connect.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.83 1998/09/20 04:51:10 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.84 1998/10/01 01:40:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -822,8 +822,8 @@ PQsetenv(PGconn *conn)
 				sprintf(envbuf, "%s=%s", envname, encoding);
 				putenv(envbuf);
 			}
-			PQclear(rtn);
 		}
+		PQclear(rtn);
 		if (!encoding)
 		{						/* this should not happen */
 			sprintf(envbuf, "%s=%s", envname, pg_encoding_to_char(MULTIBYTE));

src/interfaces/libpq/fe-lobj.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-lobj.c,v 1.16 1998/09/01 04:40:07 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-lobj.c,v 1.17 1998/10/01 01:40:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -76,7 +76,10 @@ lo_open(PGconn *conn, Oid lobjId, int mode)
 		return fd;
 	}
 	else
+	{
+		PQclear(res);
 		return -1;
+	}
 }
 
 /*
@@ -111,7 +114,10 @@ lo_close(PGconn *conn, int fd)
 		return retval;
 	}
 	else
+	{
+		PQclear(res);
 		return -1;
+	}
 }
 
 /*
@@ -151,7 +157,10 @@ lo_read(PGconn *conn, int fd, char *buf, int len)
 		return result_len;
 	}
 	else
+	{
+		PQclear(res);
 		return -1;
+	}
 }
 
 /*
@@ -192,7 +201,10 @@ lo_write(PGconn *conn, int fd, char *buf, int len)
 		return retval;
 	}
 	else
+	{
+		PQclear(res);
 		return -1;
+	}
 }
 
 /*
@@ -236,7 +248,10 @@ lo_lseek(PGconn *conn, int fd, int offset, int whence)
 		return retval;
 	}
 	else
+	{
+		PQclear(res);
 		return -1;
+	}
 }
 
 /*
@@ -273,7 +288,10 @@ lo_creat(PGconn *conn, int mode)
 		return (Oid) retval;
 	}
 	else
+	{
+		PQclear(res);
 		return InvalidOid;
+	}
 }
 
 
@@ -309,7 +327,10 @@ lo_tell(PGconn *conn, int fd)
 		return retval;
 	}
 	else
+	{
+		PQclear(res);
 		return -1;
+	}
 }
 
 /*
@@ -344,7 +365,10 @@ lo_unlink(PGconn *conn, Oid lobjId)
 		return retval;
 	}
 	else
+	{
+		PQclear(res);
 		return -1;
+	}
 }
 
 /*

src/interfaces/libpq/libpq-fe.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: libpq-fe.h,v 1.43 1998/09/18 16:46:06 momjian Exp $
+ * $Id: libpq-fe.h,v 1.44 1998/10/01 01:40:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -67,6 +67,8 @@ extern		"C"
 /* PGnotify represents the occurrence of a NOTIFY message.
  * Ideally this would be an opaque typedef, but it's so simple that it's
  * unlikely to change.
+ * NOTE: in Postgres 6.4 and later, the be_pid is the notifying backend's,
+ * whereas in earlier versions it was always your own backend's PID.
  */
 	typedef struct pgNotify
 	{
@@ -78,7 +80,7 @@ extern		"C"
 /* PQnoticeProcessor is the function type for the notice-message callback.
  */
 
-typedef void (*PQnoticeProcessor) (void * arg, const char * message);
+	typedef void (*PQnoticeProcessor) (void * arg, const char * message);
 
 /* Print options for PQprint() */
   
@@ -219,15 +221,16 @@ typedef void (*PQnoticeProcessor) (void * arg, const char * message);
 	 * use
 	 */
 	extern PGresult *PQfn(PGconn *conn,
-									  int fnid,
-									  int *result_buf,
-									  int *result_len,
-									  int result_is_int,
-									  PQArgBlock *args,
-									  int nargs);
+						  int fnid,
+						  int *result_buf,
+						  int *result_len,
+						  int result_is_int,
+						  PQArgBlock *args,
+						  int nargs);
 
 	/* Accessor functions for PGresult objects */
 	extern ExecStatusType PQresultStatus(PGresult *res);
+	extern const char *PQresultErrorMessage(PGresult *res);
 	extern int	PQntuples(PGresult *res);
 	extern int	PQnfields(PGresult *res);
 	extern int	PQbinaryTuples(PGresult *res);
@@ -246,35 +249,39 @@ typedef void (*PQnoticeProcessor) (void * arg, const char * message);
 	/* Delete a PGresult */
 	extern void PQclear(PGresult *res);
 
-	/* Make an empty PGresult with given status (some apps find this useful) */
+	/* Make an empty PGresult with given status (some apps find this useful).
+	 * If conn is not NULL and status indicates an error, the conn's
+	 * errorMessage is copied.
+	 */
 	extern PGresult * PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status);
 
 /* === in fe-print.c === */
 
-	extern void PQprint(FILE *fout,		/* output stream */
-									PGresult *res,
-									PQprintOpt *ps);	/* option structure */
+	extern void PQprint(FILE *fout,			/* output stream */
+						PGresult *res,
+						PQprintOpt *ps);	/* option structure */
 
 	/*
 	 * PQdisplayTuples() is a better version of PQprintTuples(), but both
 	 * are obsoleted by PQprint().
 	 */
 	extern void PQdisplayTuples(PGresult *res,
-											FILE *fp,	/* where to send the
-														 * output */
-											int fillAlign,		/* pad the fields with
-																 * spaces */
-											const char *fieldSep,		/* field separator */
-											int printHeader,	/* display headers? */
-											int quiet);
+								FILE *fp,			/* where to send the
+													 * output */
+								int fillAlign,		/* pad the fields with
+													 * spaces */
+								const char *fieldSep,	/* field separator */
+								int printHeader,	/* display headers? */
+								int quiet);
+
 	extern void PQprintTuples(PGresult *res,
-										  FILE *fout,	/* output stream */
-										  int printAttName,		/* print attribute names
-																 * or not */
-										  int terseOutput,		/* delimiter bars or
-																 * not? */
-										  int width);	/* width of column, if
-														 * 0, use variable width */
+							  FILE *fout,			/* output stream */
+							  int printAttName,		/* print attribute names
+													 * or not */
+							  int terseOutput,		/* delimiter bars or
+													 * not? */
+							  int width);			/* width of column, if
+													 * 0, use variable width */
 
 #ifdef MULTIBYTE
 	extern int	PQmblen(unsigned char *s);

src/interfaces/libpq/libpq-int.h

@@ -11,7 +11,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: libpq-int.h,v 1.3 1998/09/03 02:10:53 momjian Exp $
+ * $Id: libpq-int.h,v 1.4 1998/10/01 01:40:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -78,7 +78,7 @@
 		char	   *value;		/* actual value */
 	} PGresAttValue;
 
- struct pg_result
+	struct pg_result
 	{
 		int			ntups;
 		int			numAttributes;
@@ -91,7 +91,15 @@
 												 * last insert query */
 		int			binary;		/* binary tuple values if binary == 1,
 								 * otherwise ASCII */
+		/* NOTE: conn is kept here only for the temporary convenience of
+		 * applications that rely on it being here.  It will go away in a
+		 * future release, because relying on it is a bad idea --- what if
+		 * the PGresult has outlived the PGconn?  About the only thing it was
+		 * really good for was fetching the errorMessage, and we stash that
+		 * here now anyway.
+		 */
 		PGconn		*conn;		/* connection we did the query on */
+		char		*errMsg;	/* error message, or NULL if no error */
 	};
 
 /* PGAsyncStatusType defines the state of the query-execution state machine */
@@ -174,12 +182,8 @@
 		PGresult		*result;	/* result being constructed */
 		PGresAttValue	*curTuple;	/* tuple currently being read */
 
-		/* Message space.  Placed last for code-size reasons.
-		 * errorMessage is the message last returned to the application.
-		 * When asyncStatus=READY, asyncErrorMessage is the pending message
-		 * that will be put in errorMessage by PQgetResult. */
+		/* Message space.  Placed last for code-size reasons. */
 		char		errorMessage[ERROR_MSG_LENGTH];
-		char		asyncErrorMessage[ERROR_MSG_LENGTH];
 	};
 
 /* ----------------
@@ -197,6 +201,7 @@ extern int	pqPacketSend(PGconn *conn, const char *buf, size_t len);
 
 /* === in fe-exec.c === */
 
+extern void pqSetResultError(PGresult *res, const char *msg);
 extern void pqClearAsyncResult(PGconn *conn);
 
 /* === in fe-misc.c === */

src/interfaces/libpq/libpqdll.def

@@ -63,3 +63,4 @@ EXPORTS
 	lo_unlink		@ 60
 	lo_import		@ 61
 	lo_export		@ 62
+	PQresultErrorMessage	@ 63