--- a/Filename.st	Mon Sep 09 14:45:03 2019 +0200
+++ b/Filename.st	Mon Sep 09 16:15:21 2019 +0200
@@ -6924,7 +6924,7 @@
 
     ^ self species named:
         (self name
-         , self species suffixSeparator asString
+         , self species suffixSeparator
          , aSuffix asString)
 
     "
@@ -6951,6 +6951,8 @@
      '/foo/bar.c/baz.c' asFilename addSuffix:'st'
      '/foo/bar.c/baz' asFilename addSuffix:'st'
     "
+
+    "Modified: / 09-09-2019 / 16:14:44 / Stefan Vogel"
 !
 
 hasSuffix:aSuffixString
@@ -7109,13 +7111,20 @@
      If the name already has a suffix, the new suffix replaces it;
      otherwise, the new suffix is simply appended to the name."
 
+    |prefixName|
+
+    prefixName := self nameWithoutSuffix.
     aSuffix isEmptyOrNil ifTrue:[
-        ^ self.
+        prefixName = nameString ifTrue:[
+            "same filename"
+            ^ self.
+        ].
+        ^ self species named:prefixName
     ].
 
     ^ self species named:
-        (self nameWithoutSuffix
-         , self class suffixSeparator asString
+        (prefixName
+         , self class suffixSeparator
          , aSuffix asString)
 
     "
@@ -7129,7 +7138,10 @@
      '.' asFilename withSuffix:nil
 
      'abc.st' asFilename withSuffix:'o'
+     'abc.st' asFilename withSuffix:$o
+     'abc.st' asFilename withSuffix:''
      'abc' asFilename withSuffix:'o'
+     'abc' asFilename withSuffix:''
      'a.b.c' asFilename withSuffix:'o'
      'a.b.c.' asFilename withSuffix:'o'
      '.b.c.' asFilename withSuffix:'o'
@@ -7145,6 +7157,7 @@
 
     "Modified: / 07-09-1995 / 11:15:42 / claus"
     "Modified: / 07-11-2006 / 13:58:45 / cg"
+    "Modified (comment): / 09-09-2019 / 15:42:45 / Stefan Vogel"
 !
 
 withoutSuffix