mg(1) copy file in dired mode

[Mark Lumsden]

In dired mode, if you try to copy a file without giving the new path a
file name, similar to:

cp /xdir/ydir/filname /xdir/

mg fails silently and doesn't copy the file into 'xdir' by using the
existing filename as the copied filename.

This diff uses the existing filename as the new filename if none is
specified. Comments/ok?

Mark

Index: dired.c
===================================================================
RCS file: /cvs/src/usr.bin/mg/dired.c,v
retrieving revision 1.85
diff -u -p -u -p -r1.85 dired.c
--- dired.c     25 Jun 2019 13:51:47 -0000      1.85
+++ dired.c     25 Jun 2019 15:22:19 -0000
@@ -445,6 +445,7 @@ d_expunge(int f, int n)
 int
 d_copy(int f, int n)
 {
+       struct stat      statbuf;
        char             frname[NFILEN], toname[NFILEN], sname[NFILEN];
        char            *topath, *bufp;
        int              ret;
@@ -471,6 +472,18 @@ d_copy(int f, int n)
                return (FALSE);

        topath = adjustname(toname, TRUE);
+       if (stat(topath, &statbuf) == 0) {
+               if (S_ISDIR(statbuf.st_mode)) {
+                       off = snprintf(toname, sizeof(toname), "%s/%s",
+                           topath, sname);
+                       if (off < 0 || off >= sizeof(toname) - 1) {
+                               dobeep();
+                               ewprintf("Directory name too long");
+                               return (FALSE);
+                       }
+                       topath = adjustname(toname, TRUE);
+               }
+       }
        ret = (copy(frname, topath) >= 0) ? TRUE : FALSE;
        if (ret != TRUE)
                return (ret);