reapply buffer size patch to fixup out-of-order patches.

Reference: /n/atom/patch/applied/diffsync
Date: Mon Sep 28 07:09:12 CES 2015
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/diff/diffreg.c	Mon Sep 28 07:08:46 2015
+++ /sys/src/cmd/diff/diffreg.c	Mon Sep 28 07:08:48 2015
@@ -33,7 +33,7 @@
 *	through the lines of file0, developing a vector klist
 *	of "k-candidates". At step i a k-candidate is a matched
 *	pair of lines x,y (x in file0 y in file1) such that
-*	there is a common subsequence of lenght k
+*	there is a common subsequence of length k
 *	between the first i lines of file0 and the first y 
 *	lines of file1, but there is no such subsequence for
 *	any smaller y. x is the earliest possible mate to y
@@ -51,9 +51,9 @@
 *	and placed in the array J by unravel.
 *
 *	With J in hand, the matches there recorded are
-*	check'ed against reality to assure that no spurious
+*	checked against reality to assure that no spurious
 *	matches have crept in due to hashing. If they have,
-*	they are broken, and "jackpot " is recorded--a harmless
+*	they are broken, and "jackpot" is recorded--a harmless
 *	matter except that a true match for a spuriously
 *	mated line may now be unnecessarily reported as a change.
 *
@@ -188,8 +188,14 @@
 newcand(int x, int  y, int pred)
 {
 	struct cand *q;
+	static int nalloc;
 
-	clist = REALLOC(clist, struct cand, (clen+1));
+	if(clen == nalloc){
+		if(nalloc == 0)
+			nalloc = 1;
+		nalloc <<= 1;
+	}
+	clist = REALLOC(clist, struct cand, nalloc);
 	q = clist + clen;
 	q->x = x;
 	q->y = y;
@@ -316,7 +322,7 @@
 	flushchanges();
 }
 
-#define BUF 4096
+#define BUF 32768
 static int
 cmp(Biobuf* b1, Biobuf* b2)
 {