patch 8.0.0716: not easy to start Vim cleanly
Problem: Not easy to start Vim cleanly without changing the viminfo file.
Not possible to know whether the -i command line flag was used.
Solution: Add the --clean command line argument. Add the 'viminfofile'
option. Add "-u DEFAULTS".
diff --git a/src/option.c b/src/option.c
index 39aef6e..8e91fae 100644
--- a/src/option.c
+++ b/src/option.c
@@ -2986,6 +2986,15 @@
{(char_u *)0L, (char_u *)0L}
#endif
SCRIPTID_INIT},
+ {"viminfofile", "vif", P_STRING|P_ONECOMMA|P_NODUP|P_SECURE|P_VI_DEF,
+#ifdef FEAT_VIMINFO
+ (char_u *)&p_viminfofile, PV_NONE,
+ {(char_u *)"", (char_u *)0L}
+#else
+ (char_u *)NULL, PV_NONE,
+ {(char_u *)0L, (char_u *)0L}
+#endif
+ SCRIPTID_INIT},
{"virtualedit", "ve", P_STRING|P_ONECOMMA|P_NODUP|P_VI_DEF
|P_VIM|P_CURSWANT,
#ifdef FEAT_VIRTUALEDIT