delta/git.git/cache-tree.c, branch jk/robustify-parse-commit

Convert "struct cache_entry *" to "const ..." wherever possible

2013-07-09T16:12:48+00:00

I attempted to make index_state->cache[] a "const struct cache_entry **"
to find out how existing entries in index are modified and where. The
question I have is what do we do if we really need to keep track of on-disk
changes in the index. The result is

 - diff-lib.c: setting CE_UPTODATE

 - name-hash.c: setting CE_HASHED

 - preload-index.c, read-cache.c, unpack-trees.c and
   builtin/update-index: obvious

 - entry.c: write_entry() may refresh the checked out entry via
   fill_stat_cache_info(). This causes "non-const struct cache_entry
   *" in builtin/apply.c, builtin/checkout-index.c and
   builtin/checkout.c

 - builtin/ls-files.c: --with-tree changes stagemask and may set
   CE_UPDATE

Of these, write_entry() and its call sites are probably most
interesting because it modifies on-disk info. But this is stat info
and can be retrieved via refresh, at least for porcelain
commands. Other just uses ce_flags for local purposes.

So, keeping track of "dirty" entries is just a matter of setting a
flag in index modification functions exposed by read-cache.c. Except
unpack-trees, the rest of the code base does not do anything funny
behind read-cache's back.

The actual patch is less valueable than the summary above. But if
anyone wants to re-identify the above sites. Applying this patch, then
this:

    diff --git a/cache.h b/cache.h
    index 430d021..1692891 100644
    --- a/cache.h
    +++ b/cache.h
    @@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode)
     #define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)

     struct index_state {
    -	struct cache_entry **cache;
    +	const struct cache_entry **cache;
     	unsigned int version;
     	unsigned int cache_nr, cache_alloc, cache_changed;
     	struct string_list *resolve_undo;

will help quickly identify them without bogus warnings.

Signed-off-by: Nguyễn Thái Ngọc Duy 
Signed-off-by: Junio C Hamano

cache-tree: invalidate i-t-a paths after generating trees

2012-12-16T07:04:22+00:00

Intent-to-add entries used to forbid writing trees so it was not a
problem. After commit 3f6d56d (commit: ignore intent-to-add entries
instead of refusing - 2012-02-07), we can generate trees from an index
with i-t-a entries.

However, the commit forgets to invalidate all paths leading to i-t-a
entries. With fully valid cache-tree (e.g. after commit or
write-tree), diff operations may prefer cache-tree to index and not
see i-t-a entries in the index, because cache-tree does not have them.

Reported-by: Jonathon Mah 
Signed-off-by: Nguyễn Thái Ngọc Duy 
Signed-off-by: Junio C Hamano

cache-tree: fix writing cache-tree when CE_REMOVE is present

2012-12-16T07:04:22+00:00

entry_count is used in update_one() for two purposes:

1. to skip through the number of processed entries in in-memory index
2. to record the number of entries this cache-tree covers on disk

Unfortunately when CE_REMOVE is present these numbers are not the same
because CE_REMOVE entries are automatically removed before writing to
disk but entry_count is not adjusted and still counts CE_REMOVE
entries.

Separate the two use cases into two different variables. #1 is taken
care by the new field count in struct cache_tree_sub and entry_count
is prepared for #2.

Signed-off-by: Nguyễn Thái Ngọc Duy 
Signed-off-by: Junio C Hamano

cache-tree: replace "for" loops in update_one with "while" loops

2012-12-16T07:04:22+00:00

The loops in update_one can be increased in two different ways: step
by one for files and by  for directories. "for" loop is not
suitable for this as it always steps by one and special handling is
required for directories. Replace them with "while" loops for clarity.

Signed-off-by: Nguyễn Thái Ngọc Duy 
Signed-off-by: Junio C Hamano

cache-tree: remove dead i-t-a code in verify_cache()

2012-12-16T07:04:21+00:00

This code is added in 331fcb5 (git add --intent-to-add: do not let an
empty blob be committed by accident - 2008-11-28) to forbid committing
when i-t-a entries are present. When we allow that, we forgot to
remove this.

Noticed-by: Junio C Hamano 
Signed-off-by: Nguyễn Thái Ngọc Duy 
Signed-off-by: Junio C Hamano

Merge branch 'nd/cache-tree-api-refactor'

2012-02-13T06:42:42+00:00

* nd/cache-tree-api-refactor:
  cache-tree: update API to take abitrary flags

Merge branch 'jc/maint-commit-ignore-i-t-a'

2012-02-13T06:42:10+00:00

* jc/maint-commit-ignore-i-t-a:
  commit: ignore intent-to-add entries instead of refusing

Conflicts:
	cache-tree.c

cache-tree: update API to take abitrary flags

2012-02-08T00:35:43+00:00

Signed-off-by: Nguyễn Thái Ngọc Duy 
Signed-off-by: Junio C Hamano

commit: ignore intent-to-add entries instead of refusing

2012-02-07T20:14:40+00:00

Originally, "git add -N" was introduced to help users from forgetting to
add new files to the index before they ran "git commit -a".  As an attempt
to help them further so that they do not forget to say "-a", "git commit"
to commit the index as-is was taught to error out, reminding the user that
they may have forgotten to add the final contents of the paths before
running the command.

This turned out to be a false "safety" that is useless.  If the user made
changes to already tracked paths and paths added with "git add -N", and
then ran "git add" to register the final contents of the paths added with
"git add -N", "git commit" will happily create a commit out of the index,
without including the local changes made to the already tracked paths. It
was not a useful "safety" measure to prevent "forgetful" mistakes from
happening.

It turns out that this behaviour is not just a useless false "safety", but
actively hurts use cases of "git add -N" that were discovered later and
have become popular, namely, to tell Git to be aware of these paths added
by "git add -N", so that commands like "git status" and "git diff" would
include them in their output, even though the user is not interested in
including them in the next commit they are going to make.

Fix this ancient UI mistake, and instead make a commit from the index
ignoring the paths added by "git add -N" without adding real contents.

Based on the work by Nguyễn Thái Ngọc Duy, and helped by injection of
sanity from Jonathan Nieder and others on the Git mailing list.

Signed-off-by: Junio C Hamano

Refactor cache_tree_update idiom from commit

2011-12-06T22:57:36+00:00

We'll need to safely create or update the cache-tree data of the_index
from other places.  While at it, give it an argument that lets us
silence the messages produced by unmerged entries (which prevent it
from working).

Signed-off-by: Thomas Rast 
Signed-off-by: Junio C Hamano