xdiff: delete local variables and initialize/free xdfile_t directly

These local variables are essentially a hand-rolled additional
implementation of xdl_free_ctx() inlined into xdl_prepare_ctx(). Modify
the code to use the existing xdl_free_ctx() function so there aren't
two ways to free such variables.

Signed-off-by: Ezekiel Newren <ezekielnewren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: ezekielnewren

xdiff/xprepare.c

@@ -134,99 +134,81 @@ static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t
 }
 
 
+static void xdl_free_ctx(xdfile_t *xdf)
+{
+	xdl_free(xdf->rhash);
+	xdl_free(xdf->rindex);
+	xdl_free(xdf->rchg - 1);
+	xdl_free(xdf->ha);
+	xdl_free(xdf->recs);
+	xdl_cha_free(&xdf->rcha);
+}
+
+
 static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_t const *xpp,
 			   xdlclassifier_t *cf, xdfile_t *xdf) {
-	unsigned int hbits;
-	long nrec, hsize, bsize;
+	long bsize;
 	unsigned long hav;
 	char const *blk, *cur, *top, *prev;
 	xrecord_t *crec;
-	xrecord_t **recs;
-	xrecord_t **rhash;
-	unsigned long *ha;
-	char *rchg;
-	long *rindex;
 
-	ha = NULL;
-	rindex = NULL;
-	rchg = NULL;
-	rhash = NULL;
-	recs = NULL;
+	xdf->ha = NULL;
+	xdf->rindex = NULL;
+	xdf->rchg = NULL;
+	xdf->rhash = NULL;
+	xdf->recs = NULL;
 
 	if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0)
 		goto abort;
-	if (!XDL_ALLOC_ARRAY(recs, narec))
+	if (!XDL_ALLOC_ARRAY(xdf->recs, narec))
 		goto abort;
 
-	hbits = xdl_hashbits((unsigned int) narec);
-	hsize = 1 << hbits;
-	if (!XDL_CALLOC_ARRAY(rhash, hsize))
+	xdf->hbits = xdl_hashbits((unsigned int) narec);
+	if (!XDL_CALLOC_ARRAY(xdf->rhash, 1 << xdf->hbits))
 		goto abort;
 
-	nrec = 0;
+	xdf->nrec = 0;
 	if ((cur = blk = xdl_mmfile_first(mf, &bsize))) {
 		for (top = blk + bsize; cur < top; ) {
 			prev = cur;
 			hav = xdl_hash_record(&cur, top, xpp->flags);
-			if (XDL_ALLOC_GROW(recs, nrec + 1, narec))
+			if (XDL_ALLOC_GROW(xdf->recs, xdf->nrec + 1, narec))
 				goto abort;
 			if (!(crec = xdl_cha_alloc(&xdf->rcha)))
 				goto abort;
 			crec->ptr = prev;
 			crec->size = (long) (cur - prev);
 			crec->ha = hav;
-			recs[nrec++] = crec;
-			if (xdl_classify_record(pass, cf, rhash, hbits, crec) < 0)
+			xdf->recs[xdf->nrec++] = crec;
+			if (xdl_classify_record(pass, cf, xdf->rhash, xdf->hbits, crec) < 0)
 				goto abort;
 		}
 	}
 
-	if (!XDL_CALLOC_ARRAY(rchg, nrec + 2))
+	if (!XDL_CALLOC_ARRAY(xdf->rchg, xdf->nrec + 2))
 		goto abort;
 
 	if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) &&
 	    (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF)) {
-		if (!XDL_ALLOC_ARRAY(rindex, nrec + 1))
+		if (!XDL_ALLOC_ARRAY(xdf->rindex, xdf->nrec + 1))
 			goto abort;
-		if (!XDL_ALLOC_ARRAY(ha, nrec + 1))
+		if (!XDL_ALLOC_ARRAY(xdf->ha, xdf->nrec + 1))
 			goto abort;
 	}
 
-	xdf->nrec = nrec;
-	xdf->recs = recs;
-	xdf->hbits = hbits;
-	xdf->rhash = rhash;
-	xdf->rchg = rchg + 1;
-	xdf->rindex = rindex;
+	xdf->rchg += 1;
 	xdf->nreff = 0;
-	xdf->ha = ha;
 	xdf->dstart = 0;
-	xdf->dend = nrec - 1;
+	xdf->dend = xdf->nrec - 1;
 
 	return 0;
 
 abort:
-	xdl_free(ha);
-	xdl_free(rindex);
-	xdl_free(rchg);
-	xdl_free(rhash);
-	xdl_free(recs);
-	xdl_cha_free(&xdf->rcha);
+	xdl_free_ctx(xdf);
 	return -1;
 }
 
 
-static void xdl_free_ctx(xdfile_t *xdf) {
-
-	xdl_free(xdf->rhash);
-	xdl_free(xdf->rindex);
-	xdl_free(xdf->rchg - 1);
-	xdl_free(xdf->ha);
-	xdl_free(xdf->recs);
-	xdl_cha_free(&xdf->rcha);
-}
-
-
 void xdl_free_env(xdfenv_t *xe) {
 
 	xdl_free_ctx(&xe->xdf2);