libpq: Trace all messages received from the server

Not all messages that libpq received from the server would be sent
through our message tracing logic.  This commit tries to fix that by
introducing a new function pqParseDone which make it harder to forget
about doing so.

The messages that we now newly send through our tracing logic are:

- CopyData (received by COPY TO STDOUT)
- Authentication requests
- NegotiateProtocolVersion
- Some ErrorResponse messages during connection startup
- ReadyForQuery when received after a FunctionCall message

Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Discussion: https://postgr.es/m/CAGECzQSoPHtZ4xe0raJ6FYSEiPPS+YWXBhOGo+Y1YecLgknF3g@mail.gmail.com

1 files changed, 8 insertions, 4 deletions

diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 246055df960..ab308a0580f 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3797,7 +3797,7 @@ keep_going:						/* We will come back to here until there is
 						return PGRES_POLLING_READING;
 					}
 					/* OK, we read the message; mark data consumed */
-					conn->inStart = conn->inCursor;
+					pqParseDone(conn, conn->inCursor);
 
 					/*
 					 * Before 7.2, the postmaster didn't always end its
@@ -3847,7 +3847,7 @@ keep_going:						/* We will come back to here until there is
 						goto error_return;
 					}
 					/* OK, we read the message; mark data consumed */
-					conn->inStart = conn->inCursor;
+					pqParseDone(conn, conn->inCursor);
 
 					/*
 					 * If error is "cannot connect now", try the next host if
@@ -3876,7 +3876,7 @@ keep_going:						/* We will come back to here until there is
 						goto error_return;
 					}
 					/* OK, we read the message; mark data consumed */
-					conn->inStart = conn->inCursor;
+					pqParseDone(conn, conn->inCursor);
 					goto error_return;
 				}
 
@@ -3901,7 +3901,11 @@ keep_going:						/* We will come back to here until there is
 				 */
 				res = pg_fe_sendauth(areq, msgLength, conn);
 
-				/* OK, we have processed the message; mark data consumed */
+				/*
+				 * OK, we have processed the message; mark data consumed.  We
+				 * don't call pqParseDone here because we already traced this
+				 * message inside pg_fe_sendauth.
+				 */
 				conn->inStart = conn->inCursor;
 
 				if (res != STATUS_OK)