diff --git a/src/dict.c b/src/dict.c
index 34ba3e0..9b85900 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -370,13 +370,33 @@
     int
 dict_add_string(dict_T *d, char *key, char_u *str)
 {
+    return dict_add_string_len(d, key, str, -1);
+}
+
+/*
+ * Add a string entry to dictionary "d".
+ * "str" will be copied to allocated memory.
+ * When "len" is -1 use the whole string, otherwise only this many bytes.
+ * Returns FAIL when out of memory and when key already exists.
+ */
+    int
+dict_add_string_len(dict_T *d, char *key, char_u *str, int len)
+{
     dictitem_T	*item;
+    char_u	*val = NULL;
 
     item = dictitem_alloc((char_u *)key);
     if (item == NULL)
 	return FAIL;
     item->di_tv.v_type = VAR_STRING;
-    item->di_tv.vval.v_string = str != NULL ? vim_strsave(str) : NULL;
+    if (str != NULL)
+    {
+	if (len == -1)
+	    val = vim_strsave(str);
+	else
+	    val = vim_strnsave(str, len);
+    }
+    item->di_tv.vval.v_string = val;
     if (dict_add(d, item) == FAIL)
     {
 	dictitem_free(item);
diff --git a/src/memline.c b/src/memline.c
index 9f08266..d79e7ce 100644
--- a/src/memline.c
+++ b/src/memline.c
@@ -2055,21 +2055,16 @@
 	if (read_eintr(fd, &b0, sizeof(b0)) == sizeof(b0))
 	{
 	    if (ml_check_b0_id(&b0) == FAIL)
-		dict_add_string(d, "error",
-			       vim_strsave((char_u *)"Not a swap file"));
+		dict_add_string(d, "error", (char_u *)"Not a swap file");
 	    else if (b0_magic_wrong(&b0))
-		dict_add_string(d, "error",
-			       vim_strsave((char_u *)"Magic number mismatch"));
+		dict_add_string(d, "error", (char_u *)"Magic number mismatch");
 	    else
 	    {
 		/* we have swap information */
-		dict_add_string(d, "version", vim_strnsave(b0.b0_version, 10));
-		dict_add_string(d, "user",
-				     vim_strnsave(b0.b0_uname, B0_UNAME_SIZE));
-		dict_add_string(d, "host",
-				     vim_strnsave(b0.b0_hname, B0_HNAME_SIZE));
-		dict_add_string(d, "fname",
-				 vim_strnsave(b0.b0_fname, B0_FNAME_SIZE_ORG));
+		dict_add_string_len(d, "version", b0.b0_version, 10);
+		dict_add_string_len(d, "user", b0.b0_uname, B0_UNAME_SIZE);
+		dict_add_string_len(d, "host", b0.b0_hname, B0_HNAME_SIZE);
+		dict_add_string_len(d, "fname", b0.b0_fname, B0_FNAME_SIZE_ORG);
 
 		dict_add_number(d, "pid", char_to_long(b0.b0_pid));
 		dict_add_number(d, "mtime", char_to_long(b0.b0_mtime));
@@ -2080,12 +2075,11 @@
 	    }
 	}
 	else
-	    dict_add_string(d, "error",
-				    vim_strsave((char_u *)"Cannot read file"));
+	    dict_add_string(d, "error", (char_u *)"Cannot read file");
 	close(fd);
     }
     else
-	dict_add_string(d, "error", vim_strsave((char_u *)"Cannot open file"));
+	dict_add_string(d, "error", (char_u *)"Cannot open file");
 }
 #endif
 
diff --git a/src/proto/dict.pro b/src/proto/dict.pro
index 94ed2a0..b09a647 100644
--- a/src/proto/dict.pro
+++ b/src/proto/dict.pro
@@ -15,6 +15,7 @@
 int dict_add(dict_T *d, dictitem_T *item);
 int dict_add_number(dict_T *d, char *key, varnumber_T nr);
 int dict_add_string(dict_T *d, char *key, char_u *str);
+int dict_add_string_len(dict_T *d, char *key, char_u *str, int len);
 int dict_add_list(dict_T *d, char *key, list_T *list);
 int dict_add_dict(dict_T *d, char *key, dict_T *dict);
 long dict_len(dict_T *d);
diff --git a/src/version.c b/src/version.c
index 3150da9..dc11358 100644
--- a/src/version.c
+++ b/src/version.c
@@ -800,6 +800,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    642,
+/**/
     641,
 /**/
     640,