xdiff: do away with xdl_mmfile_next()

Given our simple mmfile structure, xdl_mmfile_next() calls are
redundant. Do away with calls to them.

Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

xdiff/xdiff.h

@@ -106,7 +106,6 @@ typedef struct s_bdiffparam {
 #define xdl_realloc(ptr,x) realloc(ptr,x)
 
 void *xdl_mmfile_first(mmfile_t *mmf, long *size);
-void *xdl_mmfile_next(mmfile_t *mmf, long *size);
 long xdl_mmfile_size(mmfile_t *mmf);
 
 int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,

xdiff/xprepare.c

@@ -168,12 +168,7 @@ static int xdl_prepare_ctx(mmfile_t *mf, long narec, xpparam_t const *xpp,
 
 	nrec = 0;
 	if ((cur = blk = xdl_mmfile_first(mf, &bsize)) != NULL) {
-		for (top = blk + bsize;;) {
-			if (cur >= top) {
-				if (!(cur = blk = xdl_mmfile_next(mf, &bsize)))
-					break;
-				top = blk + bsize;
-			}
+		for (top = blk + bsize; cur < top; ) {
 			prev = cur;
 			hav = xdl_hash_record(&cur, top, xpp->flags);
 			if (nrec >= narec) {

xdiff/xutils.c

@@ -67,12 +67,6 @@ void *xdl_mmfile_first(mmfile_t *mmf, long *size)
 }
 
 
-void *xdl_mmfile_next(mmfile_t *mmf, long *size)
-{
-	return NULL;
-}
-
-
 long xdl_mmfile_size(mmfile_t *mmf)
 {
 	return mmf->size;
@@ -160,13 +154,7 @@ long xdl_guess_lines(mmfile_t *mf, long sample) {
 	char const *data, *cur, *top;
 
 	if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
-		for (top = data + size; nl < sample;) {
-			if (cur >= top) {
-				tsize += (long) (cur - data);
-				if (!(cur = data = xdl_mmfile_next(mf, &size)))
-					break;
-				top = data + size;
-			}
+		for (top = data + size; nl < sample && cur < top; ) {
 			nl++;
 			if (!(cur = memchr(cur, '\n', top - cur)))
 				cur = top;