Test and refactor gettail_sep -> path_tail_with_seperator.

src/buffer.c

@@ -2713,7 +2713,7 @@ void maketitle(void)
           off += 2;
 #endif
         /* remove the file name */
-        p = gettail_sep(buf + off);
+        p = path_tail_with_seperator(buf + off);
         if (p == buf + off)
           /* must be a help buffer */
           vim_strncpy(buf + off, (char_u *)_("help"),

src/eval.c

@@ -11657,7 +11657,7 @@ static int mkdir_recurse(char_u *dir, int prot)
 
   /* Get end of directory name in "dir".
    * We're done when it's "/" or "c:/". */
-  p = gettail_sep(dir);
+  p = path_tail_with_seperator(dir);
   if (p <= get_past_head(dir))
     return OK;
 
@@ -11693,7 +11693,7 @@ static void f_mkdir(typval_T *argvars, typval_T *rettv)
   else {
     if (*path_tail(dir) == NUL)
       /* remove trailing slashes */
-      *gettail_sep(dir) = NUL;
+      *path_tail_with_seperator(dir) = NUL;
 
     if (argvars[1].v_type != VAR_UNKNOWN) {
       if (argvars[2].v_type != VAR_UNKNOWN)
@@ -12544,7 +12544,7 @@ static void f_resolve(typval_T *argvars, typval_T *rettv)
     if (!has_trailing_pathsep) {
       q = p + STRLEN(p);
       if (after_pathsep(p, q))
-        *gettail_sep(p) = NUL;
+        *path_tail_with_seperator(p) = NUL;
     }
 
     rettv->vval.v_string = p;

src/misc2.c

@@ -1609,7 +1609,7 @@ int vim_chdirfile(char_u *fname)
   char_u dir[MAXPATHL];
 
   vim_strncpy(dir, fname, MAXPATHL - 1);
-  *gettail_sep(dir) = NUL;
+  *path_tail_with_seperator(dir) = NUL;
   return os_chdir((char *)dir) == 0 ? OK : FAIL;
 }
 #endif

src/path.c

@@ -78,21 +78,19 @@ char_u *path_tail(char_u *fname)
   return tail;
 }
 
-/*
- * Get pointer to tail of "fname", including path separators.  Putting a NUL
- * here leaves the directory name.  Takes care of "c:/" and "//".
- * Always returns a valid pointer.
- */
-char_u *gettail_sep(char_u *fname)
+char_u *path_tail_with_seperator(char_u *fname)
 {
-  char_u      *p;
-  char_u      *t;
+  assert(fname != NULL);
+  char_u      *past_head;
+  char_u      *tail;
 
-  p = get_past_head(fname);     /* don't remove the '/' from "c:/file" */
-  t = path_tail(fname);
-  while (t > p && after_pathsep(fname, t))
-    --t;
-  return t;
+  // Don't remove the '/' from "c:/file".
+  past_head = get_past_head(fname);
+  tail = path_tail(fname);
+  while (tail > past_head && after_pathsep(fname, tail)) {
+    --tail;
+  }
+  return tail;
 }
 
 /*
@@ -212,7 +210,7 @@ int dir_of_file_exists(char_u *fname)
   int c;
   int retval;
 
-  p = gettail_sep(fname);
+  p = path_tail_with_seperator(fname);
   if (p == fname)
     return TRUE;
   c = *p;
@@ -1646,8 +1644,8 @@ int same_directory(char_u *f1, char_u *f2)
     return FALSE;
 
   (void)vim_FullName(f1, ffname, MAXPATHL, FALSE);
-  t1 = gettail_sep(ffname);
-  t2 = gettail_sep(f2);
+  t1 = path_tail_with_seperator(ffname);
+  t2 = path_tail_with_seperator(f2);
   return t1 - ffname == t2 - f2
          && pathcmp((char *)ffname, (char *)f2, (int)(t1 - ffname)) == 0;
 }

src/path.h

@@ -19,7 +19,7 @@ typedef enum file_comparison {
 /// @return Enum of type FileComparison. @see FileComparison.
 FileComparison path_full_compare(char_u *s1, char_u *s2, int checkname);
 
-/// Get the tail of a path:the file name.
+/// Get the tail of a path: the file name.
 /// 
 /// @param fname A file path.
 /// @return
@@ -29,6 +29,17 @@ FileComparison path_full_compare(char_u *s1, char_u *s2, int checkname);
 ///   - Never NULL.
 char_u *path_tail(char_u *fname);
 
+/// Get pointer to tail of "fname", including path separators.
+///
+/// Takes care of "c:/" and "//". That means `path_tail_with_seperator("dir///file.txt")`
+/// will return a pointer to `"///file.txt"`.
+/// @param fname A file path.
+/// @return
+///   - Pointer to the last path seperator of `fname`, if there is any.
+///   - `fname` if it contains no path seperator.
+///   - Never NULL.
+char_u *path_tail_with_seperator(char_u *fname);
+
 int vim_ispathsep(int c);
 int vim_ispathsep_nocolon(int c);
 int vim_ispathlistsep(int c);
@@ -43,7 +54,6 @@ int gen_expand_wildcards(int num_pat, char_u **pat, int *num_file,
                          char_u ***file,
                          int flags);
 void addfile(garray_T *gap, char_u *f, int flags);
-char_u *gettail_sep(char_u *fname);
 char_u *getnextcomp(char_u *fname);
 char_u *get_past_head(char_u *path);
 char_u *concat_str(char_u *str1, char_u *str2);

src/spell.c

@@ -8507,7 +8507,7 @@ spell_add_word (
        * file.  We may need to create the "spell" directory first.  We
        * already checked the runtime directory is writable in
        * init_spellfile(). */
-      if (!dir_of_file_exists(fname) && (p = gettail_sep(fname)) != fname) {
+      if (!dir_of_file_exists(fname) && (p = path_tail_with_seperator(fname)) != fname) {
         int c = *p;
 
         /* The directory doesn't exist.  Try creating it and opening

test/unit/path.moon

@@ -8,6 +8,7 @@ typedef enum file_comparison {
 } FileComparison;
 FileComparison path_full_compare(char_u *s1, char_u *s2, int checkname);
 char_u *path_tail(char_u *fname);
+char_u *path_tail_with_seperator(char_u *fname);
 ]]
 
 -- import constants parsed by ffi
@@ -62,3 +63,25 @@ describe 'path function', ->
 
     it 'returns an empty string if file ends in a slash', ->
       eq '', path_tail 'directory/'
+
+  describe 'path_tail_with_seperator', ->
+    path_tail_with_seperator = (file) ->
+      res = path.path_tail_with_seperator (to_cstr file)
+      neq NULL, res
+      ffi.string res
+
+    it 'returns the tail of a file together with its seperator', ->
+      eq '///file.txt', path_tail_with_seperator 'directory///file.txt'
+
+    it 'returns an empty string when given an empty file name', ->
+      eq '', path_tail_with_seperator ''
+
+    it 'returns only the seperator if there is a traling seperator', ->
+      eq '/', path_tail_with_seperator 'some/directory/'
+
+    it 'cuts a leading seperator', ->
+      eq 'file.txt', path_tail_with_seperator '/file.txt'
+      eq '', path_tail_with_seperator '/'
+
+    it 'returns the whole file name if there is no seperator', ->
+      eq 'file.txt', path_tail_with_seperator 'file.txt'