postgres.git / summary / log / commit / refs

commit    ac6e8753707337d338e3a5fdb99d4f593ebc2df5
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Wed Oct 22 22:42:01 2014 +0000
First released in: 9.5.0, 9.0.19, 9.1.15, 9.2.10, 9.3.6, 9.4.0

    Ensure libpq reports a suitable error message on unexpected socket EOF.
    
    The EOF-detection logic in pqReadData was a bit confused about who should
    set up the error message in case the kernel gives us read-ready-but-no-data
    rather than ECONNRESET or some other explicit error condition.  Since the
    whole point of this situation is that the lower-level functions don't know
    there's anything wrong, pqReadData itself must set up the message.  But
    keep the assumption that if an errno was reported, a message was set up at
    lower levels.
    
    Per bug #11712 from Marko Tiikkaja.  It's been like this for a very long
    time, so back-patch to all supported branches.


 src/interfaces/libpq/fe-misc.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index f4e636743f7..60c9345aef7 100644
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -730,12 +730,8 @@ retry3:
 			/* ready for read */
 			break;
 		default:
-			printfPQExpBuffer(&conn->errorMessage,
-							  libpq_gettext(
-								"server closed the connection unexpectedly\n"
-				   "\tThis probably means the server terminated abnormally\n"
-							 "\tbefore or while processing the request.\n"));
-			goto definitelyFailed;
+			/* we override pqReadReady's message with something more useful */
+			goto definitelyEOF;
 	}
 
 	/*
@@ -774,9 +770,16 @@ retry4:
 
 	/*
 	 * OK, we are getting a zero read even though select() says ready. This
-	 * means the connection has been closed.  Cope.  Note that errorMessage
-	 * has been set already.
+	 * means the connection has been closed.  Cope.
 	 */
+definitelyEOF:
+	printfPQExpBuffer(&conn->errorMessage,
+					  libpq_gettext(
+								"server closed the connection unexpectedly\n"
+				   "\tThis probably means the server terminated abnormally\n"
+							 "\tbefore or while processing the request.\n"));
+
+	/* Come here if lower-level code already set a suitable errorMessage */
 definitelyFailed:
 	conn->status = CONNECTION_BAD;		/* No more connection to backend */
 	pqsecure_close(conn);


[parent: 98170fa46507]