diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 2ca8c057b9..233456fd90 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -290,8 +290,6 @@ pqParseInput3(PGconn *conn)
 						/* First 'T' in a query sequence */
 						if (getRowDescriptions(conn, msgLength))
 							return;
-						/* getRowDescriptions() moves inStart itself */
-						continue;
 					}
 					else
 					{
@@ -337,8 +335,7 @@ pqParseInput3(PGconn *conn)
 				case 't':		/* Parameter Description */
 					if (getParamDescriptions(conn, msgLength))
 						return;
-					/* getParamDescriptions() moves inStart itself */
-					continue;
+					break;
 				case 'D':		/* Data Row */
 					if (conn->result != NULL &&
 						conn->result->resultStatus == PGRES_TUPLES_OK)
@@ -346,8 +343,6 @@ pqParseInput3(PGconn *conn)
 						/* Read another tuple of a normal query response */
 						if (getAnotherTuple(conn, msgLength))
 							return;
-						/* getAnotherTuple() moves inStart itself */
-						continue;
 					}
 					else if (conn->result != NULL &&
 							 conn->result->resultStatus == PGRES_FATAL_ERROR)
@@ -462,7 +457,6 @@ handleSyncLoss(PGconn *conn, char id, int msgLength)
  * command for a prepared statement) containing the attribute data.
  * Returns: 0 if processed message successfully, EOF to suspend parsing
  * (the latter case is not actually used currently).
- * In the former case, conn->inStart has been advanced past the message.
  */
 static int
 getRowDescriptions(PGconn *conn, int msgLength)
@@ -577,9 +571,6 @@ getRowDescriptions(PGconn *conn, int msgLength)
 	/* Success! */
 	conn->result = result;
 
-	/* Advance inStart to show that the "T" message has been processed. */
-	conn->inStart = conn->inCursor;
-
 	/*
 	 * If we're doing a Describe, we're done, and ready to pass the result
 	 * back to the client.
@@ -603,9 +594,6 @@ advance_and_error:
 	if (result && result != conn->result)
 		PQclear(result);
 
-	/* Discard the failed message by pretending we read it */
-	conn->inStart += 5 + msgLength;
-
 	/*
 	 * Replace partially constructed result with an error result. First
 	 * discard the old result to try to win back some memory.
@@ -624,6 +612,12 @@ advance_and_error:
 	appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
 	pqSaveErrorResult(conn);
 
+	/*
+	 * Show the message as fully consumed, else pqParseInput3 will overwrite
+	 * our error with a complaint about that.
+	 */
+	conn->inCursor = conn->inStart + 5 + msgLength;
+
 	/*
 	 * Return zero to allow input parsing to continue.  Subsequent "D"
 	 * messages will be ignored until we get to end of data, since an error
@@ -635,12 +629,8 @@ advance_and_error:
 /*
  * parseInput subroutine to read a 't' (ParameterDescription) message.
  * We'll build a new PGresult structure containing the parameter data.
- * Returns: 0 if completed message, EOF if not enough data yet.
- * In the former case, conn->inStart has been advanced past the message.
- *
- * Note that if we run out of data, we have to release the partially
- * constructed PGresult, and rebuild it again next time.  Fortunately,
- * that shouldn't happen often, since 't' messages usually fit in a packet.
+ * Returns: 0 if processed message successfully, EOF to suspend parsing
+ * (the latter case is not actually used currently).
  */
 static int
 getParamDescriptions(PGconn *conn, int msgLength)
@@ -690,23 +680,16 @@ getParamDescriptions(PGconn *conn, int msgLength)
 	/* Success! */
 	conn->result = result;
 
-	/* Advance inStart to show that the "t" message has been processed. */
-	conn->inStart = conn->inCursor;
-
 	return 0;
 
 not_enough_data:
-	PQclear(result);
-	return EOF;
+	errmsg = libpq_gettext("insufficient data in \"t\" message");
 
 advance_and_error:
 	/* Discard unsaved result, if any */
 	if (result && result != conn->result)
 		PQclear(result);
 
-	/* Discard the failed message by pretending we read it */
-	conn->inStart += 5 + msgLength;
-
 	/*
 	 * Replace partially constructed result with an error result. First
 	 * discard the old result to try to win back some memory.
@@ -724,6 +707,12 @@ advance_and_error:
 	appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
 	pqSaveErrorResult(conn);
 
+	/*
+	 * Show the message as fully consumed, else pqParseInput3 will overwrite
+	 * our error with a complaint about that.
+	 */
+	conn->inCursor = conn->inStart + 5 + msgLength;
+
 	/*
 	 * Return zero to allow input parsing to continue.  Essentially, we've
 	 * replaced the COMMAND_OK result with an error result, but since this
@@ -737,7 +726,6 @@ advance_and_error:
  * We fill rowbuf with column pointers and then call the row processor.
  * Returns: 0 if processed message successfully, EOF to suspend parsing
  * (the latter case is not actually used currently).
- * In the former case, conn->inStart has been advanced past the message.
  */
 static int
 getAnotherTuple(PGconn *conn, int msgLength)
@@ -817,21 +805,14 @@ getAnotherTuple(PGconn *conn, int msgLength)
 		goto advance_and_error;
 	}
 
-	/* Advance inStart to show that the "D" message has been processed. */
-	conn->inStart = conn->inCursor;
-
 	/* Process the collected row */
 	errmsg = NULL;
 	if (pqRowProcessor(conn, &errmsg))
 		return 0;				/* normal, successful exit */
 
-	goto set_error_result;		/* pqRowProcessor failed, report it */
+	/* pqRowProcessor failed, fall through to report it */
 
 advance_and_error:
-	/* Discard the failed message by pretending we read it */
-	conn->inStart += 5 + msgLength;
-
-set_error_result:
 
 	/*
 	 * Replace partially constructed result with an error result. First
@@ -851,6 +832,12 @@ set_error_result:
 	appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
 	pqSaveErrorResult(conn);
 
+	/*
+	 * Show the message as fully consumed, else pqParseInput3 will overwrite
+	 * our error with a complaint about that.
+	 */
+	conn->inCursor = conn->inStart + 5 + msgLength;
+
 	/*
 	 * Return zero to allow input parsing to continue.  Subsequent "D"
 	 * messages will be ignored until we get to end of data, since an error