patch 8.0.0074
Problem:    Cannot make Vim fail on an internal error.
Solution:   Add IEMSG() and IEMSG2(). (Domenique Pelle)  Avoid reporting an
            internal error without mentioning where.
diff --git a/src/blowfish.c b/src/blowfish.c
index d3f5cff..ac9b088 100644
--- a/src/blowfish.c
+++ b/src/blowfish.c
@@ -426,7 +426,7 @@
     keylen = (int)STRLEN(key) / 2;
     if (keylen == 0)
     {
-	EMSG(_("E831: bf_key_init() called with empty password"));
+	IEMSG(_("E831: bf_key_init() called with empty password"));
 	return;
     }
     for (i = 0; i < keylen; i++)