PPC32: Make strncpy clear the unused part of the destination.

arch/ppc/lib/string.S

@@ -78,6 +78,8 @@ _GLOBAL(strcpy)
 	bne	1b
 	blr
 
+/* This clears out any unused part of the destination buffer,
+   just as the libc version does.  -- paulus */
 _GLOBAL(strncpy)
 	cmpwi	0,r5,0
 	beqlr
@@ -88,6 +90,12 @@ _GLOBAL(strncpy)
 	cmpwi	0,r0,0
 	stbu	r0,1(r6)
 	bdnzf	2,1b		/* dec ctr, branch if ctr != 0 && !cr0.eq */
+	bnelr			/* if we didn't hit a null char, we're done */
+	mfctr	r5
+	cmpwi	0,r5,0		/* any space left in destination buffer? */
+	beqlr			/* we know r0 == 0 here */
+2:	stbu	r0,1(r6)	/* clear it out if so */
+	bdnz	2b
 	blr
 
 _GLOBAL(strcat)