From 0d950df8e9c43872be7fac7487bab8e549e9c19e Mon Sep 17 00:00:00 2001
From: mingrammer <mingrammer@gmail.com>
Date: Mon, 9 Mar 2020 22:41:14 +0900
Subject: [PATCH] fix(edges): prevent the attrs from overwriting by empty
 string

---
 diagrams/__init__.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/diagrams/__init__.py b/diagrams/__init__.py
index f052079f..ca6ebb6b 100644
--- a/diagrams/__init__.py
+++ b/diagrams/__init__.py
@@ -445,9 +445,12 @@ class Edge:
         self._attrs["xlabel"] = label if label else xlabel
         self._attrs["color"] = color
         self._attrs["style"] = style
-        self._attrs["fontcolor"] = fontcolor
-        self._attrs["fontname"] = fontname
-        self._attrs["fontsize"] = fontsize
+        if fontcolor:
+            self._attrs["fontcolor"] = fontcolor
+        if fontname:
+            self._attrs["fontname"] = fontname
+        if fontsize:
+            self._attrs["fontsize"] = fontsize
 
     def __sub__(self, other: Union["Node", "Edge", List["Node"]]):
         """Implement Self - Node or Edge and Self - [Nodes]"""