Fix buffer overrun in constructing error message.

If the server returned an error longer than 4096 bytes, we would overrun
the buffer by two bytes. If you're unlucky, that could lead to a crash,
and it consistently did on Windows.

Per report from Andrus Moor.

1 files changed, 5 insertions, 7 deletions

diff --git a/statement.c b/statement.c
index 20c9c06..57e7aa2 100644
--- a/statement.c
+++ b/statement.c
@@ -1299,12 +1299,9 @@ SC_create_errorinfo(const StatementClass *self)
 	{
 		pos = strlen(msg);
 
-		if (detailmsg)
-		{
-			msg[pos++] = ';';
-			msg[pos++] = '\n';
-		}
-		strncpy_null(msg + pos, wmsg, sizeof(msg) - pos);
+		snprintf(&msg[pos], sizeof(msg) - pos, "%s%s",
+				 detailmsg ? ";\n" : "",
+				 wmsg);
 		ermsg = msg;
 		detailmsg = TRUE;
 	}
@@ -1316,7 +1313,8 @@ SC_create_errorinfo(const StatementClass *self)
 		if (!resmsg && (wmsg = CC_get_errormsg(conn)) && wmsg[0] != '\0')
 		{
 			pos = strlen(msg);
-			snprintf(&msg[pos], sizeof(msg) - pos, ";\n%s", CC_get_errormsg(conn));
+			snprintf(&msg[pos], sizeof(msg) - pos,
+					 ";\n%s", CC_get_errormsg(conn));
 		}
 
 		ermsg = msg;