tdb2: fix intermittant failure in run-50-multiple-freelists-fail.c

layout.c's TDB creation functions were incorrect in case of a hash
collision, causing occasional failure.  Make it always use the
(previously-failing) seed value, and fix it.

ccan/tdb2/test/layout.c

@@ -206,7 +206,7 @@ static void add_to_hashtable(struct tdb_context *tdb,
 		b_off = hbucket_off(group_start, bucket);		
 		if (tdb_read_off(tdb, b_off) == 0) {
 			tdb_write_off(tdb, b_off,
-				      encode_offset(eoff, bucket, h));
+				      encode_offset(eoff, in_group, h));
 			return;
 		}
 	}
@@ -228,7 +228,8 @@ static struct tle_freetable *find_ftable(struct tdb_layout *layout, unsigned num
 }
 
 /* FIXME: Support TDB_CONVERT */
-struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
+struct tdb_context *tdb_layout_get(struct tdb_layout *layout,
+				   union tdb_attribute *attr)
 {
 	unsigned int i;
 	tdb_off_t off, len, last_ftable;
@@ -264,7 +265,7 @@ struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 	/* Fill with some weird pattern. */
 	memset(mem, 0x99, off);
 	/* Now populate our header, cribbing from a real TDB header. */
-	tdb = tdb_open(NULL, TDB_INTERNAL, O_RDWR, 0, &tap_log_attr);
+	tdb = tdb_open(NULL, TDB_INTERNAL, O_RDWR, 0, attr);
 	memcpy(mem, tdb->file->map_ptr, sizeof(struct tdb_header));
 
 	/* Mug the tdb we have to make it use this. */

ccan/tdb2/test/layout.h

@@ -15,7 +15,8 @@ void tdb_layout_add_hashtable(struct tdb_layout *layout,
 			      unsigned int bucket,
 			      tdb_len_t extra);
 #endif
-struct tdb_context *tdb_layout_get(struct tdb_layout *layout);
+struct tdb_context *tdb_layout_get(struct tdb_layout *layout,
+				   union tdb_attribute *attr);
 void tdb_layout_free(struct tdb_layout *layout);
 
 enum layout_type {

ccan/tdb2/test/run-03-coalesce.c

@@ -43,7 +43,7 @@ int main(int argc, char *argv[])
 	tdb_layout_add_freetable(layout);
 	len = 1024;
 	tdb_layout_add_free(layout, len, 0);
-	tdb = tdb_layout_get(layout);
+	tdb = tdb_layout_get(layout, &tap_log_attr);
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
 	ok1(free_record_length(tdb, layout->elem[1].base.off) == len);
 
@@ -66,7 +66,7 @@ int main(int argc, char *argv[])
 	tdb_layout_add_freetable(layout);
 	tdb_layout_add_free(layout, 1024, 0);
 	tdb_layout_add_used(layout, key, data, 6);
-	tdb = tdb_layout_get(layout);
+	tdb = tdb_layout_get(layout, &tap_log_attr);
 	ok1(free_record_length(tdb, layout->elem[1].base.off) == 1024);
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
 
@@ -89,7 +89,7 @@ int main(int argc, char *argv[])
 	tdb_layout_add_freetable(layout);
 	tdb_layout_add_free(layout, 1024, 0);
 	tdb_layout_add_free(layout, 2048, 0);
-	tdb = tdb_layout_get(layout);
+	tdb = tdb_layout_get(layout, &tap_log_attr);
 	ok1(free_record_length(tdb, layout->elem[1].base.off) == 1024);
 	ok1(free_record_length(tdb, layout->elem[2].base.off) == 2048);
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
@@ -116,7 +116,7 @@ int main(int argc, char *argv[])
 	tdb_layout_add_free(layout, 1024, 0);
 	tdb_layout_add_free(layout, 512, 0);
 	tdb_layout_add_used(layout, key, data, 6);
-	tdb = tdb_layout_get(layout);
+	tdb = tdb_layout_get(layout, &tap_log_attr);
 	ok1(free_record_length(tdb, layout->elem[1].base.off) == 1024);
 	ok1(free_record_length(tdb, layout->elem[2].base.off) == 512);
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
@@ -142,7 +142,7 @@ int main(int argc, char *argv[])
 	tdb_layout_add_free(layout, 1024, 0);
 	tdb_layout_add_free(layout, 512, 0);
 	tdb_layout_add_free(layout, 256, 0);
-	tdb = tdb_layout_get(layout);
+	tdb = tdb_layout_get(layout, &tap_log_attr);
 	ok1(free_record_length(tdb, layout->elem[1].base.off) == 1024);
 	ok1(free_record_length(tdb, layout->elem[2].base.off) == 512);
 	ok1(free_record_length(tdb, layout->elem[3].base.off) == 256);

ccan/tdb2/test/run-50-multiple-freelists.c

@@ -16,6 +16,12 @@ int main(int argc, char *argv[])
 	struct tdb_context *tdb;
 	struct tdb_layout *layout;
 	TDB_DATA key, data;
+	union tdb_attribute seed;
+
+	/* This seed value previously tickled a layout.c bug. */
+	seed.base.attr = TDB_ATTRIBUTE_SEED;
+	seed.seed.seed = 0xb1142bc054d035b4ULL;
+	seed.base.next = &tap_log_attr;
 
 	plan_tests(11);
 	key = tdb_mkdata("Hello", 5);
@@ -36,7 +42,7 @@ int main(int argc, char *argv[])
 	key.dsize--;
 	tdb_layout_add_used(layout, key, data, 8);
 	tdb_layout_add_free(layout, 40, 0);
-	tdb = tdb_layout_get(layout);
+	tdb = tdb_layout_get(layout, &seed);
 	ok1(tdb_check(tdb, NULL, NULL) == 0);
 
 	off = get_free(tdb, 0, 80 - sizeof(struct tdb_used_record), 0,