=== modified file 't/11strfkey.c'
--- t/11strfkey.c	2013-08-26 17:46:01 +0000
+++ t/11strfkey.c	2013-08-26 00:32:35 +0000
@@ -8,7 +8,7 @@
   char       buffer[16];
   size_t     len;
 
-  plan_tests(44);
+  plan_tests(40);
 
   tk = termkey_new_abstract("vt100", 0);
 
@@ -106,15 +106,6 @@
   is_int(len, 7, "length for sym/PageUp/0 lowerspace");
   is_str(buffer, "page up", "buffer for sym/PageUp/0 lowerspace");
 
-  /* If size of buffer is too small, strfkey should return something consistent */
-  len = termkey_strfkey(tk, buffer, 4, &key, 0);
-  is_int(len, 6, "length for sym/PageUp/0");
-  is_str(buffer, "Pag", "buffer of len 4 for sym/PageUp/0");
-
-  len = termkey_strfkey(tk, buffer, 4, &key, TERMKEY_FORMAT_LOWERSPACE);
-  is_int(len, 7, "length for sym/PageUp/0 lowerspace");
-  is_str(buffer, "pag", "buffer of len 4 for sym/PageUp/0 lowerspace");
-
   key.type = TERMKEY_TYPE_FUNCTION;
   key.code.number = 5;
   key.modifiers = 0;

=== modified file 'termkey.c'
--- termkey.c	2013-08-26 17:46:01 +0000
+++ termkey.c	2013-08-26 01:35:40 +0000
@@ -198,26 +198,19 @@
 {
   int prev_lower = 0;
   size_t l = 0;
-  while(*src && l < size - 1) {
+  while(*src && l < size) {
     if(isupper(*src) && prev_lower) {
       if(str)
         str[l++] = ' ';
-      if(l >= size - 1)
-        break;
+      if(l >= size)
+        return -1;
     }
     prev_lower = islower(*src);
     str[l++] = tolower(*src++);
   }
+  if(l >= size)
+    return -1;
   str[l] = 0;
-  /* For consistency with snprintf, return the number of bytes that would have
-   * been written, excluding '\0' */
-  while(*src) {
-    if(isupper(*src) && prev_lower) {
-      l++;
-    }
-    prev_lower = islower(*src);
-    src++; l++;
-  }
   return l;
 }