Fix up closePGconn() so that PQreset() will work on GSSAPI/SSPI connections;

the patch for those features put its cleanup code into freePGconn() which is
really the wrong place.  Remove redundant code from freePGconn() and add
comments in hopes of preventing similar mistakes in future.
Noticed while trying (futilely) to reproduce bug #3902.

src/interfaces/libpq/fe-connect.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.355 2008/01/01 19:46:00 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.356 2008/01/29 02:06:30 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1963,25 +1963,16 @@ makeEmptyPGconn(void)
 
 /*
  * freePGconn
- *	 - free the PGconn data structure
+ *	 - free an idle (closed) PGconn data structure
  *
- * When changing/adding to this function, see also closePGconn!
+ * NOTE: this should not overlap any functionality with closePGconn().
+ * Clearing/resetting of transient state belongs there; what we do here is
+ * release data that is to be held for the life of the PGconn structure.
+ * If a value ought to be cleared/freed during PQreset(), do it there not here.
  */
 static void
 freePGconn(PGconn *conn)
 {
-	PGnotify   *notify;
-	pgParameterStatus *pstatus;
-
-	if (!conn)
-		return;
-
-	pqClearAsyncResult(conn);	/* deallocate result and curTuple */
-	if (conn->sock >= 0)
-	{
-		pqsecure_close(conn);
-		closesocket(conn->sock);
-	}
 	if (conn->pghost)
 		free(conn->pghost);
 	if (conn->pghostaddr)
@@ -2011,65 +2002,13 @@ freePGconn(PGconn *conn)
 	/* Note that conn->Pfdebug is not ours to close or free */
 	if (conn->last_query)
 		free(conn->last_query);
-	pg_freeaddrinfo_all(conn->addrlist_family, conn->addrlist);
-	notify = conn->notifyHead;
-	while (notify != NULL)
-	{
-		PGnotify   *prev = notify;
-
-		notify = notify->next;
-		free(prev);
-	}
-#ifdef ENABLE_GSS
-	{
-		OM_uint32	min_s;
-
-		if (conn->gctx)
-			gss_delete_sec_context(&min_s, &conn->gctx, GSS_C_NO_BUFFER);
-		if (conn->gtarg_nam)
-			gss_release_name(&min_s, &conn->gtarg_nam);
-		if (conn->ginbuf.length)
-			gss_release_buffer(&min_s, &conn->ginbuf);
-		if (conn->goutbuf.length)
-			gss_release_buffer(&min_s, &conn->goutbuf);
-	}
-#endif
-#ifdef ENABLE_SSPI
-	{
-		if (conn->ginbuf.length)
-			free(conn->ginbuf.value);
-
-		if (conn->sspitarget)
-			free(conn->sspitarget);
-
-		if (conn->sspicred)
-		{
-			FreeCredentialsHandle(conn->sspicred);
-			free(conn->sspicred);
-		}
-		if (conn->sspictx)
-		{
-			DeleteSecurityContext(conn->sspictx);
-			free(conn->sspictx);
-		}
-	}
-#endif
-	pstatus = conn->pstatus;
-	while (pstatus != NULL)
-	{
-		pgParameterStatus *prev = pstatus;
-
-		pstatus = pstatus->next;
-		free(prev);
-	}
-	if (conn->lobjfuncs)
-		free(conn->lobjfuncs);
 	if (conn->inBuffer)
 		free(conn->inBuffer);
 	if (conn->outBuffer)
 		free(conn->outBuffer);
 	termPQExpBuffer(&conn->errorMessage);
 	termPQExpBuffer(&conn->workBuffer);
+
 	free(conn);
 
 #ifdef WIN32
@@ -2081,7 +2020,9 @@ freePGconn(PGconn *conn)
  * closePGconn
  *	 - properly close a connection to the backend
  *
- * Release all transient state, but NOT the connection parameters.
+ * This should reset or release all transient state, but NOT the connection
+ * parameters.  On exit, the PGconn should be in condition to start a fresh
+ * connection with the same parameters (see PQreset()).
  */
 static void
 closePGconn(PGconn *conn)
@@ -2105,9 +2046,10 @@ closePGconn(PGconn *conn)
 	}
 
 	/*
-	 * must reset the blocking status so a possible reconnect will work don't
-	 * call PQsetnonblocking() because it will fail if it's unable to flush
-	 * the connection.
+	 * Must reset the blocking status so a possible reconnect will work.
+	 *
+	 * Don't call PQsetnonblocking() because it will fail if it's unable to
+	 * flush the connection.
 	 */
 	conn->nonblocking = FALSE;
 
@@ -2135,7 +2077,7 @@ closePGconn(PGconn *conn)
 		notify = notify->next;
 		free(prev);
 	}
-	conn->notifyHead = NULL;
+	conn->notifyHead = conn->notifyTail = NULL;
 	pstatus = conn->pstatus;
 	while (pstatus != NULL)
 	{
@@ -2150,6 +2092,41 @@ closePGconn(PGconn *conn)
 	conn->lobjfuncs = NULL;
 	conn->inStart = conn->inCursor = conn->inEnd = 0;
 	conn->outCount = 0;
+#ifdef ENABLE_GSS
+	{
+		OM_uint32	min_s;
+
+		if (conn->gctx)
+			gss_delete_sec_context(&min_s, &conn->gctx, GSS_C_NO_BUFFER);
+		if (conn->gtarg_nam)
+			gss_release_name(&min_s, &conn->gtarg_nam);
+		if (conn->ginbuf.length)
+			gss_release_buffer(&min_s, &conn->ginbuf);
+		if (conn->goutbuf.length)
+			gss_release_buffer(&min_s, &conn->goutbuf);
+	}
+#endif
+#ifdef ENABLE_SSPI
+	if (conn->ginbuf.length)
+		free(conn->ginbuf.value);
+	conn->ginbuf.length = 0;
+	conn->ginbuf.value = NULL;
+	if (conn->sspitarget)
+		free(conn->sspitarget);
+	conn->sspitarget = NULL;
+	if (conn->sspicred)
+	{
+		FreeCredentialsHandle(conn->sspicred);
+		free(conn->sspicred);
+		conn->sspicred = NULL;
+	}
+	if (conn->sspictx)
+	{
+		DeleteSecurityContext(conn->sspictx);
+		free(conn->sspictx);
+		conn->sspictx = NULL;
+	}
+#endif
 }
 
 /*