merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/diffcore-order.c

@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2005 Junio C Hamano
+ */
+#include "cache.h"
+#include "diff.h"
+#include "diffcore.h"
+
+static char **order;
+static int order_cnt;
+
+static void prepare_order(const char *orderfile)
+{
+	int cnt, pass;
+	struct strbuf sb = STRBUF_INIT;
+	void *map;
+	char *cp, *endp;
+	ssize_t sz;
+
+	if (order)
+		return;
+
+	sz = strbuf_read_file(&sb, orderfile, 0);
+	if (sz < 0)
+		die_errno(_("failed to read orderfile '%s'"), orderfile);
+	map = strbuf_detach(&sb, NULL);
+	endp = (char *) map + sz;
+
+	for (pass = 0; pass < 2; pass++) {
+		cnt = 0;
+		cp = map;
+		while (cp < endp) {
+			char *ep;
+			for (ep = cp; ep < endp && *ep != '\n'; ep++)
+				;
+			/* cp to ep has one line */
+			if (*cp == '\n' || *cp == '#')
+				; /* comment */
+			else if (pass == 0)
+				cnt++;
+			else {
+				if (*ep == '\n') {
+					*ep = 0;
+					order[cnt] = cp;
+				} else {
+					order[cnt] = xmemdupz(cp, ep - cp);
+				}
+				cnt++;
+			}
+			if (ep < endp)
+				ep++;
+			cp = ep;
+		}
+		if (pass == 0) {
+			order_cnt = cnt;
+			ALLOC_ARRAY(order, cnt);
+		}
+	}
+}
+
+static int match_order(const char *path)
+{
+	int i;
+	static struct strbuf p = STRBUF_INIT;
+
+	for (i = 0; i < order_cnt; i++) {
+		strbuf_reset(&p);
+		strbuf_addstr(&p, path);
+		while (p.buf[0]) {
+			char *cp;
+			if (!wildmatch(order[i], p.buf, 0))
+				return i;
+			cp = strrchr(p.buf, '/');
+			if (!cp)
+				break;
+			*cp = 0;
+		}
+	}
+	return order_cnt;
+}
+
+static int compare_objs_order(const void *a_, const void *b_)
+{
+	struct obj_order const *a, *b;
+	a = (struct obj_order const *)a_;
+	b = (struct obj_order const *)b_;
+	if (a->order != b->order)
+		return a->order - b->order;
+	return a->orig_order - b->orig_order;
+}
+
+void order_objects(const char *orderfile, obj_path_fn_t obj_path,
+		   struct obj_order *objs, int nr)
+{
+	int i;
+
+	if (!nr)
+		return;
+
+	prepare_order(orderfile);
+	for (i = 0; i < nr; i++) {
+		objs[i].orig_order = i;
+		objs[i].order = match_order(obj_path(objs[i].obj));
+	}
+	QSORT(objs, nr, compare_objs_order);
+}
+
+static const char *pair_pathtwo(void *obj)
+{
+	struct diff_filepair *pair = (struct diff_filepair *)obj;
+
+	return pair->two->path;
+}
+
+void diffcore_order(const char *orderfile)
+{
+	struct diff_queue_struct *q = &diff_queued_diff;
+	struct obj_order *o;
+	int i;
+
+	if (!q->nr)
+		return;
+
+	ALLOC_ARRAY(o, q->nr);
+	for (i = 0; i < q->nr; i++)
+		o[i].obj = q->queue[i];
+	order_objects(orderfile, pair_pathtwo, o, q->nr);
+	for (i = 0; i < q->nr; i++)
+		q->queue[i] = o[i].obj;
+	free(o);
+	return;
+}