diff --git a/Lib/test/test_textwrap.py b/Lib/test/test_textwrap.py
--- a/Lib/test/test_textwrap.py
+++ b/Lib/test/test_textwrap.py
@@ -22,7 +22,7 @@
             result = []
             for i in range(len(textin)):
                 result.append("  %d: %r" % (i, textin[i]))
-            result = '\n'.join(result)
+            result = '\n'.join(result) if result else '  --'
         elif isinstance(textin, str):
             result = "  %s\n" % repr(textin)
         return result
@@ -66,6 +66,8 @@
                          "I'm glad to hear it!"])
         self.check_wrap(text, 80, [text])
 
+    def test_empty_string(self):
+        self.check_wrap('', 10, [''])
 
     def test_whitespace(self):
         # Whitespace munging and end-of-sentence detection
@@ -99,6 +101,11 @@
         expect = ["    Test    custom      tabsize."]
         self.check_wrap(text, 80, expect, tabsize=4)
 
+    def test_whitespace_trailing(self):
+        # Verify that whitespace left over at the end does not append an
+        # empty string to the end of the returned list.
+        self.check_wrap('foo  ', 3, ['foo'])
+
     def test_fix_sentence_endings(self):
         wrapper = TextWrapper(60, fix_sentence_endings=True)
 
@@ -340,6 +347,12 @@
         self.check_wrap(text, 30,
                         [" This is a sentence with", "leading whitespace."])
 
+    def test_drop_whitespace__all_whitespace(self):
+        # Check that drop_whitespace with all-whitespace input does not
+        # return an empty list.
+        self.check_wrap('  ', 10, ['  '], drop_whitespace=False)
+        self.check_wrap('  ', 10, [''], drop_whitespace=True)
+
     def test_no_drop_whitespace(self):
         # SF patch #1581073
         text = " This is a    sentence with     much whitespace."
@@ -477,6 +490,9 @@
         result = fill(self.text, 40, initial_indent="     ")
         self.check(result, expect)
 
+    def test_initial_indent__empty_string(self):
+        # Check that initial_indent does not indent the empty string.
+        self.check_wrap('', 10, [''], initial_indent='-->')
 
     def test_subsequent_indent(self):
         # Test subsequent_indent parameter
@@ -491,6 +507,17 @@
                       initial_indent="  * ", subsequent_indent="    ")
         self.check(result, expect)
 
+    def test_subsequent_indent__trailing_whitespace(self):
+        # Check that subsequent_indent with trailing whitespace in the
+        # input does not append an indented empty string to the end of
+        # the returned list.
+        self.check_wrap('hello ', 5, ['hello'], subsequent_indent='-->')
+
+    def test_subsequent_indent__long_indent(self):
+        # Check that subsequent_indent with a long indent string does not
+        # append an indented empty string to the end of the returned list.
+        self.check_wrap('foo', 2, ['fo', '-->o'], subsequent_indent='-->')
+
 
 # Despite the similar names, DedentTestCase is *not* the inverse
 # of IndentTestCase!
diff --git a/Lib/textwrap.py b/Lib/textwrap.py
--- a/Lib/textwrap.py
+++ b/Lib/textwrap.py
@@ -293,7 +293,8 @@
         chunks = self._split(text)
         if self.fix_sentence_endings:
             self._fix_sentence_endings(chunks)
-        return self._wrap_chunks(chunks)
+        # wrap() should never return an empty list.  See issue #15510.
+        return self._wrap_chunks(chunks) or ['']
 
     def fill(self, text):
         """fill(text : string) -> string