--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2010-01-10  Bruno Haible  <bruno@clisp.org>
+
+	unistr/u*-stpncpy: Fix the return value.
+	* lib/unistr.h (u8_stpncpy, u16_stpncpy, u32_stpncpy): Make the
+	description of the return value consistent with stpncpy in glibc.
+	* lib/unistr/u-stpncpy.h (FUNC): Return the pointer past the last
+	written non-NUL unit.
+
 2010-01-10  Bruno Haible  <bruno@clisp.org>
 
 	unistr/u*-next: Add missing dependencies.

--- a/lib/unistr.h
+++ b/lib/unistr.h
@@ -529,8 +529,8 @@
 extern uint32_t *
        u32_strncpy (uint32_t *dest, const uint32_t *src, size_t n);
 
-/* Copy no more than N units of SRC to DEST, returning the address of
-   the last unit written into DEST.  */
+/* Copy no more than N units of SRC to DEST.  Return a pointer past the last
+   non-NUL unit written into DEST.  */
 /* Similar to stpncpy().  */
 extern uint8_t *
        u8_stpncpy (uint8_t *dest, const uint8_t *src, size_t n);

--- a/lib/unistr/u-stpncpy.h
+++ b/lib/unistr/u-stpncpy.h
@@ -23,8 +23,12 @@
 
   /* This behavior is rarely useful, but it is here for consistency with
      strncpy and wcsncpy.  */
-  for (; n > 0; n--)
-    *dest++ = 0;
+  {
+    UNIT *destptr = dest;
 
-  return dest - 1;
+    for (; n > 0; n--)
+      *destptr++ = 0;
+  }
+
+  return dest;
 }