Undo: make "move dive computer to front" undoable

Instead of the elegant solution that just modifies the dive,
keep two copies and add either the old or the new copy. This
is primitive, but it trivially keeps the dives in the right order.
The order might change on renumbering the dive computers.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

2 files changed, 30 insertions, 15 deletions

diff --git a/core/dive.c b/core/dive.c
index ed0c5a757..e6b27e0bb 100644
--- a/core/dive.c
+++ b/core/dive.c
@@ -4151,27 +4151,42 @@ bool dive_remove_picture(struct dive *d, const char *filename)
 	return false;
 }
 
-/* this always acts on the current divecomputer of the current dive */
-void make_first_dc()
+/* clones a dive and moves given dive computer to front */
+struct dive *make_first_dc(const struct dive *d, int dc_number)
 {
-	struct divecomputer *dc = &current_dive->dc;
-	struct divecomputer *newdc = malloc(sizeof(*newdc));
-	struct divecomputer *cur_dc = current_dc; /* needs to be in a local variable so the macro isn't re-executed */
+	struct dive *res;
+	struct divecomputer *dc, *newdc, *old_dc;
+
+	/* copy the dive */
+	res = alloc_dive();
+	copy_dive(d, res);
+
+	/* make a new unique id, since we still can't handle two equal ids */
+	res->id = dive_getUniqID();
+	invalidate_dive_cache(res);
+
+	if (dc_number == 0)
+		return res;
+
+	dc = &res->dc;
+	newdc = malloc(sizeof(*newdc));
+	old_dc = get_dive_dc(res, dc_number);
 
 	/* skip the current DC in the linked list */
-	while (dc && dc->next != cur_dc)
-		dc = dc->next;
+	for (dc = &res->dc; dc && dc->next != old_dc; dc = dc->next)
+		;
 	if (!dc) {
 		free(newdc);
 		fprintf(stderr, "data inconsistent: can't find the current DC");
-		return;
+		return res;
 	}
-	dc->next = cur_dc->next;
-	*newdc = current_dive->dc;
-	current_dive->dc = *cur_dc;
-	current_dive->dc.next = newdc;
-	free(cur_dc);
-	invalidate_dive_cache(current_dive);
+	dc->next = old_dc->next;
+	*newdc = res->dc;
+	res->dc = *old_dc;
+	res->dc.next = newdc;
+	free(old_dc);
+
+	return res;
 }
 
 /* always acts on the current dive */
diff --git a/core/dive.h b/core/dive.h
index 7aea050b6..ebc127bd7 100644
--- a/core/dive.h
+++ b/core/dive.h
@@ -434,7 +434,7 @@ extern unsigned int number_of_computers(const struct dive *dive);
 extern struct divecomputer *get_dive_dc(struct dive *dive, int nr);
 extern timestamp_t dive_endtime(const struct dive *dive);
 
-extern void make_first_dc(void);
+extern struct dive *make_first_dc(const struct dive *d, int dc_number);
 extern unsigned int count_divecomputers(void);
 extern void delete_current_divecomputer(void);
 void split_divecomputer(const struct dive *src, int num, struct dive **out1, struct dive **out2);