diff --git a/builtin.cpp b/builtin.cpp
index c0372812c..fa187a17f 100644
--- a/builtin.cpp
+++ b/builtin.cpp
@@ -1086,7 +1086,8 @@ static int builtin_generic( parser_t &parser, wchar_t **argv )
 static void functions_def( const wcstring &name, wcstring &out )
 {
 	const wchar_t *desc = function_get_desc( name );
-	const wchar_t *def = function_get_definition(name);
+    wcstring def;
+    function_get_definition(name, &def);
 
 	event_t search(EVENT_ANY);
 
@@ -1169,11 +1170,10 @@ static void functions_def( const wcstring &name, wcstring &out )
 	
     
     /* This forced tab is sort of crummy - not all functions start with a tab */
-    append_format( out, L"\n\t%ls", def);
+    append_format( out, L"\n\t%ls", def.c_str());
     
     /* Append a newline before the 'end', unless there already is one there */
-    size_t deflen = wcslen(def);
-    if (deflen == 0 || def[deflen-1] != L'\n') {
+    if (! string_suffixes_string(L"\n", def)) {
         out.push_back(L'\n');
     }
     out.append(L"end\n");
@@ -3733,10 +3733,14 @@ void builtin_get_names(std::vector<completion_t> &list) {
 	}
 }
 
-const wchar_t *builtin_get_desc( const wcstring &name )
+wcstring builtin_get_desc( const wcstring &name )
 {
+    wcstring result;
 	const builtin_data_t *builtin = builtin_lookup(name);
-    return builtin ? _(builtin->desc) : NULL;
+    if (builtin) {
+        result = _(builtin->desc);
+    }
+    return result;
 }
 
 void builtin_push_io( parser_t &parser, int in )
diff --git a/builtin.h b/builtin.h
index f2093780b..a34c83cbb 100644
--- a/builtin.h
+++ b/builtin.h
@@ -155,9 +155,9 @@ void builtin_pop_io(parser_t &parser);
 
 
 /**
-   Return a one-line description of the specified builtin. This is usually a truly constant string, so we should not wrap it in a wcstring.
+   Return a one-line description of the specified builtin.
 */
-const wchar_t *builtin_get_desc( const wcstring &b );
+wcstring builtin_get_desc( const wcstring &b );
 
 
 /**
diff --git a/complete.cpp b/complete.cpp
index 2a051b397..35e0a5ebf 100644
--- a/complete.cpp
+++ b/complete.cpp
@@ -832,7 +832,7 @@ int complete_is_valid_argument( const wchar_t *str,
 static void complete_strings( std::vector<completion_t> &comp_out,
 							  const wcstring &wc_escaped,
 							  const wchar_t *desc,
-							  const wchar_t *(*desc_func)(const wcstring &),
+							  wcstring (*desc_func)(const wcstring &),
 							  std::vector<completion_t> &possible_comp,
 							  complete_flags_t flags )
 {
@@ -981,16 +981,20 @@ void completer_t::complete_cmd_desc( const wcstring &str )
 }
 
 /**
-   Returns a description for the specified function
+   Returns a description for the specified function, or an empty string if none
 */
-static const wchar_t *complete_function_desc( const wcstring &fn )
+static wcstring complete_function_desc( const wcstring &fn )
 {
+    wcstring result;
+    
 	const wchar_t *res = function_get_desc( fn );
+    if (res) {
+        result = res;
+    } else {
+        function_get_definition(fn, &result);
+    }
 
-	if( !res )
-		res = function_get_definition( fn );
-
-	return res;
+	return result;
 }
 
 
diff --git a/exec.cpp b/exec.cpp
index f8689840f..92b2a476a 100644
--- a/exec.cpp
+++ b/exec.cpp
@@ -787,12 +787,13 @@ void exec( parser_t &parser, job_t *j )
 				*/
 
 				signal_unblock();
-				const wchar_t * orig_def = function_get_definition( p->argv0() );
+                wcstring orig_def;
+                function_get_definition( p->argv0(), &orig_def );
                 
                 // function_get_named_arguments may trigger autoload, which deallocates the orig_def.
                 // We should make function_get_definition return a wcstring (but how to handle NULL...)
-                if (orig_def)
-                    def = wcsdup(orig_def);
+                if (! orig_def.empty())
+                    def = wcsdup(orig_def.c_str());
                 
 				wcstring_list_t named_arguments = function_get_named_arguments( p->argv0() );
 				shadows = function_get_shadows( p->argv0() );
diff --git a/function.cpp b/function.cpp
index 5b80391b8..166d30a55 100644
--- a/function.cpp
+++ b/function.cpp
@@ -251,10 +251,13 @@ shared_ptr<function_info_t> function_get(const wcstring &name)
     }
 }
 	
-const wchar_t *function_get_definition( const wcstring &name )
+bool function_get_definition( const wcstring &name, wcstring *out_definition )
 {
     shared_ptr<function_info_t> func = function_get(name);
-    return func ? func->definition.c_str() : NULL;
+    if (func && out_definition) {
+        out_definition->assign(func->definition);
+    }
+    return func != NULL;
 }
 
 wcstring_list_t function_get_named_arguments( const wcstring &name )
diff --git a/function.h b/function.h
index 4bf4003f7..01f5653bc 100644
--- a/function.h
+++ b/function.h
@@ -103,14 +103,10 @@ void function_add( const function_data_t &data, const parser_t &parser );
 void function_remove( const wcstring &name );
 
 /**
-    Gets a function by name.
+   Returns by reference the definition of the function with the name \c name.
+   Returns true if successful, false if no function with the given name exists.
 */
-shared_ptr<function_info_t> function_get(const wcstring &name);
-
-/**
-   Returns the definition of the function with the name \c name.
-*/
-const wchar_t *function_get_definition( const wcstring &name );
+bool function_get_definition( const wcstring &name, wcstring *out_definition );
 
 /**
    Returns the description of the function with the name \c name.
diff --git a/history.cpp b/history.cpp
index 935b2eab5..547792f45 100644
--- a/history.cpp
+++ b/history.cpp
@@ -136,18 +136,6 @@ static void escape_yaml(std::string &str);
 /** Undoes escape_yaml */
 static void unescape_yaml(std::string &str);
 
-/* Custom deleter for our shared_ptr */
-class history_item_data_deleter_t {
-    private:
-        const bool free_it;
-    public:
-    history_item_data_deleter_t(bool flag) : free_it(flag) { }
-    void operator()(const wchar_t *data) {
-        if (free_it)
-            free((void *)data);
-    }
-};
-
 /* We can merge two items if they are the same command. We use the more recent timestamp and the longer list of required paths. */
 bool history_item_t::merge(const history_item_t &item)
 {
diff --git a/wildcard.cpp b/wildcard.cpp
index e9055f9be..e27efe593 100644
--- a/wildcard.cpp
+++ b/wildcard.cpp
@@ -204,7 +204,7 @@ static bool wildcard_complete_internal(const wcstring &orig,
 									   const wchar_t *wc, 
 									   bool is_first,
 									   const wchar_t *desc,
-									   const wchar_t *(*desc_func)(const wcstring &),
+									   wcstring (*desc_func)(const wcstring &),
 									   std::vector<completion_t> &out,
 									   int flags )
 {
@@ -245,8 +245,8 @@ static bool wildcard_complete_internal(const wcstring &orig,
 				  it. If it returns something, use that as the
 				  description.
 				*/
-				const wchar_t *func_desc = desc_func( orig );
-				if( func_desc )
+				wcstring func_desc = desc_func( orig );
+				if (! func_desc.empty())
 					out_desc = func_desc;
 			}
 			
@@ -300,7 +300,7 @@ static bool wildcard_complete_internal(const wcstring &orig,
 bool wildcard_complete(const wcstring &str,
 					   const wchar_t *wc,
 					   const wchar_t *desc,						
-					   const wchar_t *(*desc_func)(const wcstring &),
+					   wcstring (*desc_func)(const wcstring &),
 					   std::vector<completion_t> &out,
 					   int flags )
 {
diff --git a/wildcard.h b/wildcard.h
index cf7aa10f0..40830f0cc 100644
--- a/wildcard.h
+++ b/wildcard.h
@@ -89,7 +89,7 @@ int wildcard_has( const wchar_t *str, int internal );
 bool wildcard_complete(const wcstring &str,
 					   const wchar_t *wc,
 					   const wchar_t *desc,						
-					   const wchar_t *(*desc_func)(const wcstring &),
+					   wcstring (*desc_func)(const wcstring &),
 					   std::vector<completion_t> &out,
 					   expand_flags_t flags );