Improve swap_link with temp link before removing link.

Update test, now test_swap_link pass.

swap_link.py

@@ -21,12 +21,27 @@ def swap_link(lnk, tgt):
         elif tpath.readlink().resolve() == lnpath.resolve() :
             raise Exception("Target is a link to link to be fixed...")
     
-    try:
-        lnpath.unlink()
-    except Exception(e):
-        raise Exception("Failed to unlink lnk. Check permissions!")
-
-    lnpath = Path(lnk)
+    tmp_suffix = 0
+    tmp_prefix = 'temp'
+    tmp_name = tmp_prefix + str(tmp_suffix)
+    tmp_path = Path(lnpath.parent / tmp_name)
+    while tmp_path.exists() or tmp_path.is_symlink():
+        tmp_suffix += 1
+        tmp_name = tmp_prefix + str(tmp_suffix)
+        tmp_path = Path(lnk.parent / tmp_name)
 
     sym_path = relpath(tgt, lnk)[3:]
-    lnpath.symlink_to(sym_path)
+
+    try:
+        tmp_path.symlink_to(sym_path)
+    except Exception:
+        print(f"Attempted to create tmp link: {tmp_name}")
+        raise Exception("Failed to create new symlink. Check permissions!")
+
+    try:
+        lnpath.unlink()
+    except Exception:
+        tmp_path.unlink()
+        raise Exception("Failed to remove broken link. Check permissions!")
+    
+    tmp_path.rename(lnk)