vim-patch:8.1.1791: 'completeslash' also applies to globpath()

Problem:    'completeslash' also applies to globpath().
Solution:   Add the WILD_IGNORE_COMPLETESLASH flag. (test by Yasuhiro
            Matsumoto, closes vim/vim#4760)

src/nvim/eval/funcs.c

@@ -4007,7 +4007,7 @@ static void f_glob(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 /// "globpath()" function
 static void f_globpath(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  int flags = 0;  // Flags for globpath.
+  int flags = WILD_IGNORE_COMPLETESLASH;  // Flags for globpath.
   bool error = false;
 
   // Return a string, or a list if the optional third argument is non-zero.

src/nvim/ex_getln.c

@@ -4990,7 +4990,7 @@ ExpandFromContext (
     char_u *pat,
     int *num_file,
     char_u ***file,
-    int options              /* EW_ flags */
+    int options              // WILD_ flags
 )
 {
   regmatch_T regmatch;
@@ -5053,7 +5053,7 @@ ExpandFromContext (
     if (free_pat)
       xfree(pat);
 #ifdef BACKSLASH_IN_FILENAME
-    if (p_csl[0] != NUL) {
+    if (p_csl[0] != NUL && (options & WILD_IGNORE_COMPLETESLASH) == 0) {
       for (int i = 0; i < *num_file; i++) {
         char_u *ptr = (*file)[i];
         while (*ptr != NUL) {

src/nvim/testdir/test_ins_complete.vim

@@ -367,17 +367,15 @@ endfunc
 
 " Test for insert path completion with completeslash option
 func Test_ins_completeslash()
-  if !has('win32')
-    return
-  endif
-  
+  CheckMSWindows
+
   call mkdir('Xdir')
 
   let orig_shellslash = &shellslash
   set cpt&
 
   new
-  
+
   set noshellslash
 
   set completeslash=
@@ -408,7 +406,12 @@ func Test_ins_completeslash()
   %bw!
   call delete('Xdir', 'rf')
 
+  set noshellslash
+  set completeslash=slash
+  call assert_true(stridx(globpath(&rtp, 'syntax/*.vim', 1, 1)[0], '\') != -1)
+
   let &shellslash = orig_shellslash
+  set completeslash=
 endfunc
 
 func Test_pum_with_folds_two_tabs()