* lib.c (upop): New function.

* lib.h (upop): Declared.

* txr.c (txr_main): Two bugfixes. One is that the argument -
was being pushed back twice resulting in *args* being ("-" "-").
This is because the option processing loop checked for "-" and pushed
it back into args, and then some logic after the loop pushed arg back
into args again. But, these pushes were wrong because they push
back a different cons cell; we would like to be able to
do (ldiff *full-args* *args*). This is solved by upop, which provides
one element of undo. After upop, we can restore the prior list
from the undo save location.

1 files changed, 6 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 4365c4b8..2b5bd031 100644
--- a/lib.c
+++ b/lib.c
@@ -426,6 +426,12 @@ val pop(val *plist)
   return ret;
 }
 
+val upop(val *plist, val *pundo)
+{
+  *pundo = *plist;
+  return pop(plist);
+}
+
 val push(val value, val *plist)
 {
   /* Unsafe for mutating object fields: use mpush macro. */