stem: handle corner case of leading dot filename

Author: scivision

+stdlib/stem.m

@@ -1,12 +1,19 @@
 %% STEM filename without directory or suffix
 
-function p = stem(p)
+function st = stem(p)
 % arguments
 %   p (1,1) string
 % end
 
-[~, p] = fileparts(p);
+[~, n, s] = fileparts(p);
+
+if stdlib.len(n)
+  st = n;
+else
+  st = s;
+end
 
 end
 
 %!assert(stem('/a/b.c'), 'b')
+%!assert(stem("a/b/.c"), ".c")

+stdlib/with_suffix.m

@@ -16,15 +16,7 @@
 s = stdlib.stem(p);
 
 if stdlib.len(s) == 0
-  if stdlib.len(stdlib.filename(p))
-    if ischar(r)
-      f = strcat(p, suffix);
-    else
-      f = p + suffix;
-    end
-  else
-    f = stdlib.join(p, suffix, false);
-  end
+  f = stdlib.join(p, suffix, false);
   return
 end
 

test/TestFilePure.m

@@ -13,7 +13,9 @@
   {"a/b/c.txt.gz", "c.txt.gz"}
 };
 
-p_stem ={{"/a/b/c", "c"}, {"/a/b/c/", ""}, {"a/b/c/", ""}, {"a/b/c.txt", "c"}, {"a/b/c.txt.gz", "c.txt"}}
+p_stem ={{"/a/b/c", "c"}, {"/a/b/c/", ""}, {"a/b/c/", ""}, ...
+{"a/b/c.txt", "c"}, {"a/b/c.txt.gz", "c.txt"}, ...
+{"a/b/.c", ".c"}}
 
 p_join = {{"", "", ""}, ...
 {"a", "", "a"}, ...