1 files changed, 32 insertions, 30 deletions

diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index 5fe6209a0a..df4a6d52c4 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -1616,9 +1616,15 @@ do_arglist (
   char_u      *p;
   int match;
 
-  /*
-   * Collect all file name arguments in "new_ga".
-   */
+  // Set default argument for ":argadd" command.
+  if (what == AL_ADD && *str == NUL) {
+    if (curbuf->b_ffname == NULL) {
+      return FAIL;
+    }
+    str = curbuf->b_fname;
+  }
+
+  // Collect all file name arguments in "new_ga".
   get_arglist(&new_ga, str);
 
   if (what == AL_DEL) {
@@ -1990,11 +1996,17 @@ void ex_argdelete(exarg_T *eap)
       } else if (curwin->w_arg_idx > eap->line1) {
         curwin->w_arg_idx = (int)eap->line1;
       }
+      if (ARGCOUNT == 0) {
+          curwin->w_arg_idx = 0;
+      } else if (curwin->w_arg_idx >= ARGCOUNT) {
+          curwin->w_arg_idx = ARGCOUNT - 1;
+      }
     }
-  } else if (*eap->arg == NUL)
+  } else if (*eap->arg == NUL) {
     EMSG(_(e_argreq));
-  else
+  } else {
     do_arglist(eap->arg, AL_DEL, 0);
+  }
   maketitle();
 }
 
@@ -2221,6 +2233,7 @@ alist_add_list (
     int after                  /* where to add: 0 = before first one */
 )
 {
+  int old_argcount = ARGCOUNT;
   ga_grow(&ALIST(curwin)->al_ga, count);
   {
     if (after < 0)
@@ -2235,8 +2248,9 @@ alist_add_list (
       ARGLIST[after + i].ae_fnum = buflist_add(files[i], BLN_LISTED);
     }
     ALIST(curwin)->al_ga.ga_len += count;
-    if (curwin->w_arg_idx >= after)
-      ++curwin->w_arg_idx;
+    if (old_argcount > 0 && curwin->w_arg_idx >= after) {
+      curwin->w_arg_idx += count;
+    }
     return after;
   }
 }
@@ -2481,32 +2495,31 @@ int source_level(void *cookie)
   return ((struct source_cookie *)cookie)->level;
 }
 
-
-#if (defined(WIN32) && defined(FEAT_CSCOPE)) || defined(HAVE_FD_CLOEXEC)
-# define USE_FOPEN_NOINH
-/*
- * Special function to open a file without handle inheritance.
- * When possible the handle is closed on exec().
- */
+/// Special function to open a file without handle inheritance.
+/// If possible the handle is closed on exec().
 static FILE *fopen_noinh_readbin(char *filename)
 {
+#ifdef WIN32
+  int fd_tmp = os_open(filename, O_RDONLY | O_BINARY | O_NOINHERIT, 0);
+#else
   int fd_tmp = os_open(filename, O_RDONLY, 0);
+#endif
 
-  if (fd_tmp < 0)
+  if (fd_tmp < 0) {
     return NULL;
+  }
 
-# ifdef HAVE_FD_CLOEXEC
+#ifdef HAVE_FD_CLOEXEC
   {
     int fdflags = fcntl(fd_tmp, F_GETFD);
     if (fdflags >= 0 && (fdflags & FD_CLOEXEC) == 0) {
       (void)fcntl(fd_tmp, F_SETFD, fdflags | FD_CLOEXEC);
     }
   }
-# endif
+#endif
 
   return fdopen(fd_tmp, READBIN);
 }
-#endif
 
 
 /*
@@ -2560,11 +2573,7 @@ do_source (
   /* Apply SourcePre autocommands, they may get the file. */
   apply_autocmds(EVENT_SOURCEPRE, fname_exp, fname_exp, FALSE, curbuf);
 
-#ifdef USE_FOPEN_NOINH
   cookie.fp = fopen_noinh_readbin((char *)fname_exp);
-#else
-  cookie.fp = mch_fopen((char *)fname_exp, READBIN);
-#endif
   if (cookie.fp == NULL && check_other) {
     /*
      * Try again, replacing file name ".vimrc" by "_vimrc" or vice versa,
@@ -2573,15 +2582,8 @@ do_source (
     p = path_tail(fname_exp);
     if ((*p == '.' || *p == '_')
         && (STRICMP(p + 1, "nvimrc") == 0 || STRICMP(p + 1, "exrc") == 0)) {
-      if (*p == '_')
-        *p = '.';
-      else
-        *p = '_';
-#ifdef USE_FOPEN_NOINH
+      *p = (*p == '_') ? '.' : '_';
       cookie.fp = fopen_noinh_readbin((char *)fname_exp);
-#else
-      cookie.fp = mch_fopen((char *)fname_exp, READBIN);
-#endif
     }
   }