Add auto-fill-on-delete. When deleting an 'A'uto created partition

sysinstall will automatically expand the previous partition to take up
the freed up space.  So you can 'D'elete /home and /usr will get the
combined space, or you can 'D'elete /tmp and /var will get the combined space.

This gives the user, developer, or lay person a huge amount of flexibility
in constructing partitions from an 'A'uto base.  It takes only 3 or 4
keystrokes to achieve virtually any combination of having or not having
a /tmp and/or /home after doing an 'A'uto create.

Change 'A'uto creation of /var/tmp to 'A'uto creation /tmp, which should
be less controversial.

MFC after:	6 days

1 files changed, 13 insertions, 2 deletions

diff --git a/lib/libdisk/chunk.c b/lib/libdisk/chunk.c
index 83c247a..b2e9d3d 100644
--- a/lib/libdisk/chunk.c
+++ b/lib/libdisk/chunk.c
@@ -363,6 +363,7 @@ Delete_Chunk(struct disk *d, struct chunk *c)
 {
 	struct chunk *c1=0, *c2, *c3;
 	chunk_e type = c->type;
+	long offset = c->offset;
 
 	if(type == whole)
 		return 1;
@@ -398,9 +399,19 @@ Delete_Chunk(struct disk *d, struct chunk *c)
 	}
 	return 1;
     scan:
+	/*
+	 * Collapse multiple unused elements together, and attempt
+	 * to extend the previous chunk into the freed chunk.
+	 */
 	for(c2 = c1->part; c2; c2 = c2->next) {
-		if (c2->type != unused)
-			continue;
+		if (c2->type != unused) {
+			if (c2->offset + c2->size != offset ||
+			    (c2->flags & CHUNK_AUTO_SIZE) == 0 ||
+			    (c2->flags & CHUNK_NEWFS) == 0) {
+				continue;
+			}
+			/* else extend into free area */
+		}
 		if (!c2->next)
 			continue;
 		if (c2->next->type != unused)