Make "update-cache --refresh" do what it really should do: just
refresh the "stat" information.

We need this after having done a "read-tree", for example, when the
stat information does not match the checked-out tree, and we want to
start getting efficient cache matching against the parts of the tree
that are already up-to-date.

Fix up commit-tree/diff-tree user interface issues.

No, this doesn't make them easy to use, but makes diff-tree use
the "-r" flag for "recursive" (not "-R") and makes commit-tree
use AUTHOR_xxx environment flags (not COMMITTER_xxx) to match what
it actually does.

Oops. Fix bad initialization of the "seen" array, causing us to not
properly clear the reference count at init time. It happened to work
for me by pure luck.

Until it broke, and my unreferenced commit suddenly looked referenced
again. Fixed.

Oops, the actual 'printf' for missing objects was missing.

Which made fsck very quiet about objects it hadn't found. So add
it.

We'll need to make things like these optional, because it's
perfectly ok to have partial history if you don't want it,
and don't want to go backwards. But for development, it's best
to always complain about missing sha1 object files that are
referenced from somewhere else.

Add connectivity tracking to fsck.

This shows that I've lost track of one commit already. Most likely
because I forgot to update the .dircache/HEAD file when doing a
commit, so that the next commit referenced not the top-of-tree, but
the one older commit.

Having dangling commits is fine (in fact, you should always have
at least _one_ dangling commit in the top-of-tree). But it's
good to know about them.

Fix off-by-one error in removal of cache entry.

Also make the return value of "cache_name_pos()" be sane: positive
or zero if we found it (it's the index into the cache array), and
"-pos-1" to indicate where it should go if we didn't.

Fix diff-tree recursion.

And, perhaps more importantly, fix the fact that if a filename changed from a
directory to a file (or vice versa), we must consider it a delete and an add,
not a "filechange".

Simplify "diff-tree" output, and only keep track of one single name-base.

During original development I had different name-bases for source and
destination, so that I could make the output show how it got removed
from "tree a" and added to "tree b", but we don't want that. We only
do recursive diffs on anything where the bases are exactly the same,
so we might as well just work with a single base.

Also, make the output for "changed" be a single line, since people
hated the separate '<' / '>' format. They were right. It sucked.

Add "-R" flag to "diff-tree", so that it will recursively traverse a tree of trees
as it diffs them.

This makes diff-tree usable again in the new world order.

Make "update-cache" a bit friendlier to use (and harder to mis-use).

It now requires the "--add" flag before you add any new files, and
a "--remove" file if you want to mark files for removal. And giving
it the "--refresh" flag makes it just update all the files that it
already knows about.

This implements the new "recursive tree" write-tree.

It's got some debugging printouts etc still in it, but testing on the
kernel seems to show that it does indeed fix the issue with huge tree
files for each commit.

Make fsck-cache warn about old-style tree objects that have full
pathnames in them. We're migrating away from that.

This will cause tons of warnings for the current "sparse" archive,
but hell, better now than later.

Teach "fsck" and "read-tree" about recursive tree-nodes.

This is totally untested, since we can't actually _write_ things that
way yet, but I'll get to that next, I hope. That should fix the
huge wasted space for kernel-sized tree objects.

Make "fsck-cache" print out all the root commits it finds.

Once I do the reference tracking, I'll also make it print out all the
HEAD commits it finds, which is even more interesting.

Add "diff-tree" program to show which files have changed between two trees.

Very useful for creating diffs efficiently, and in general to see what has
changed in the namespace.

Export "cache_name_compare()" helper function.

The "diff-tree" program needs it.

Make "read-tree" read the tree into the current directory cache.

It will no longer update the actual working directory, just the
cache. To update the working directory, you need to use "checkout-cache".

Make "write_cache()" and friends available as generic routines.

This is needed for the change to make "read-tree" just read into the
cache (and then you do a "checkout-cache" to update your current dir
contents).

Fix "checkout-cache.c" mis-use of read_sha1_file() interface.

It's supposed to test the returned file type, not think that read_sha1_file()
tests it. Confusion from "cat-file" command line usage.

Fix up "checkout-cache" a bit

Make the warnings have newlines, and don't stop "checkout-cache -a"
just because a file already exists.

Add a "checkout-cache" command which does what the name suggests.

I'll also eventually change "read-tree" to only update the cache
information, instead of doing a checkout of the tree. Much nicer.

Make the cache stat information comparator public.

Like the cache filename finder, it's a generically useful function,
rather than something specific to the current "show-diff" thing.

Make "cache_name_pos()" available to others.

It finds the cache entry position for a given name, and is
generally useful. Sure, everybody can just scan the active
cache array, but since it's sorted, you actually want to
search it with a binary search, so let's not duplicate that
logic all over the place.

Fix missing return values and some error tests for empty index files

Patches from Dave Jones and Ingo Molnar, but since I don't have any
infrastructure in place to use the old patch applicator scripts I
am trying to build up, I ended up fixing the thing by hand instead.

Credit where credit is due, though. Nice to see that people are
taking a look at the project even in this early stage.

Make fsck-cache start parsing the object types, and checking their
internal format.

This doesn't yet check the reachability information, but we're getting
there.. Slowly.

Add "-lz" to link line to get in zlib.

Not all Linux distributions seem to need it (notably not YDL on ppc64), but
enough ones obviously do.

Add new fsck-cache to Makefile.

This is what happens when there are no nice tools to tell you to do things
properly.

Add first cut at "fsck-cache" that validates the SHA1 object store.

It doesn't complain about mine. But it also doesn't yet check for
inter-object reachability etc.

Add "check_sha1_signature()" helper function

And fix up header declarations.

Factor out "read_sha1_file" into mapping/inflating/unmapping.

This allows us to also actually check the sha1 hash using these
routines. Needed for the "fsck" thing.

Use "-Wall -O2" for the compiler to get more warnings.

And fix up the warnings that it pointed out. Let's keep the tree
clean from early on.

Not that the code is very beautiful anyway ;)

Make "cat-file" output the file contents to stdout.

New syntax: "cat-file -t <sha1>" shows the tag, while "cat-file <tag> <sha1>"
outputs the file contents after checking that the supplied tag matches.

Make read-tree actually unpack the whole tree.

I needed this to make a "sparse" archive conversion from my old
BitKeeper tree data. The scripts to do the conversion are just
incredibly ugly, but they seem to validate the notion that you
can actually use this silly 'git' thing to save your history in.

Add copyright notices.

The tool interface sucks (especially "committing" information, which is just
me doing everything by hand from the command line), but I think this is in
theory actually a viable way of describing the world. So copyright it.

Initial revision of "git", the information manager from hell