dir.c: fix ignore processing within not-ignored directories

As of 95c6f271 "dir.c: unify is_excluded and is_path_excluded APIs", the
is_excluded API no longer recurses into directories that match an ignore
pattern, and returns the directory's ignored state for all contained paths.

This is OK for normal ignore patterns, i.e. ignoring a directory affects
the entire contents recursively.

Unfortunately, this also "works" for negated ignore patterns ('!dir'), i.e.
the entire contents is "not-ignored" recursively, regardless of ignore
patterns that match the contents directly.

In prep_exclude, skip recursing into a directory only if it is really
ignored (i.e. the ignore pattern is not negated).

Signed-off-by: Karsten Blees <blees@dcon.de>
Tested-by: Øystein Walle <oystwa@gmail.com>
Reviewed-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'fc/zsh-leftover-bits'

* fc/zsh-leftover-bits:
  completion: zsh: improve bash script loading
  completion: synchronize zsh wrapper
  completion: cleanup zsh wrapper
Merge branch 'fc/completion'

* fc/completion:
  completion: remove __git_index_file_list_filter()
  completion: add space after completed filename
  completion: add hack to enable file mode in bash < 4
  completion: refactor __git_complete_index_file()
  completion: refactor diff_index wrappers
  completion: use __gitcompadd for __gitcomp_file
  completion; remove unuseful comments
  completion: document tilde expansion failure in tests
  completion: add file completion tests
Merge branch 'an/diff-index-doc'

* an/diff-index-doc:
  Documentation/diff-index: mention two modes of operation
Merge branch 'rh/merge-options-doc-fix'

* rh/merge-options-doc-fix:
  Documentation/merge-options.txt: restore `-e` option
Merge branch 'rs/empty-archive'

Fixes tests added in 1.8.2 era that are broken on BSDs.

* rs/empty-archive:
  t5004: resurrect original empty tar archive test
  t5004: avoid using tar for checking emptiness of archive
Merge branch 'fc/fast-export-persistent-marks'

Optimization for fast-export by avoiding unnecessarily resolving
arbitrary object name and parsing object when only presence and
type information is necessary, etc.

* fc/fast-export-persistent-marks:
  fast-{import,export}: use get_sha1_hex() to read from marks file
  fast-export: don't parse commits while reading marks file
  fast-export: do not parse non-commit objects while reading marks file
Merge branch 'nd/clone-local-with-colon'

"git clone foo/bar:baz" cannot be a request to clone from a remote
over git-over-ssh specified in the scp style.  Detect this case and
clone from a local repository at "foo/bar:baz".

* nd/clone-local-with-colon:
  clone: allow cloning local paths with colons in them
Merge branch 'vv/help-unknown-ref'

Detect "git merge foo" that might have meant "git merge origin/foo"
and give an error message that is more specific than "foo is not
something we can merge".

* vv/help-unknown-ref:
  merge: use help_unknown_ref()
  help: add help_unknown_ref()
Merge branch 'fc/macos-x-clipped-write'

Mac OS X does not like to write(2) more than INT_MAX number of
bytes.

* fc/macos-x-clipped-write:
  compate/clipped-write.c: large write(2) fails on Mac OS X/XNU
Merge branch 'da/darwin'

Newer MacOS X encourages the programs to compile and link with
their CommonCrypto, not with OpenSSL.

* da/darwin:
  imap-send: eliminate HMAC deprecation warnings on Mac OS X
  cache.h: eliminate SHA-1 deprecation warnings on Mac OS X
  Makefile: add support for Apple CommonCrypto facility
  Makefile: fix default regex settings on Darwin
Merge branch 'jc/t5551-posix-sed-bre'

POSIX fix for a test script.

* jc/t5551-posix-sed-bre:
  t5551: do not use unportable sed '\+'
Merge branch 'kb/ancestry-path-threedots'

"git log --ancestry-path A...B" did not work as expected, as it did
not pay attention to the fact that the merge base between A and B
was the bottom of the range being specified.

* kb/ancestry-path-threedots:
  revision.c: treat A...B merge bases as if manually specified
  t6019: demonstrate --ancestry-path A...B breakage
Merge branch 'mk/combine-diff-context-horizon-fix'

"git diff -c -p" was not showing a deleted line from a hunk when
another hunk immediately begins where the earlier one ends.

* mk/combine-diff-context-horizon-fix:
  combine-diff.c: Fix output when changes are exactly 3 lines apart
Merge branch 'tr/coverage'

Update the test coverage support that was left to bitrot for some
time.

* tr/coverage:
  coverage: build coverage-untested-functions by default
  coverage: set DEFAULT_TEST_TARGET to avoid using prove
  coverage: do not delete .gcno files before building
  coverage: split build target into compile and test
Merge branch 'jk/fetch-always-update-tracking'

"git fetch origin master" unlike "git fetch origin" or "git fetch"
did not update "refs/remotes/origin/master"; this was an early
design decision to keep the update of remote tracking branches
predictable, but in practice it turns out that people find it more
convenient to opportunisticly update them whenever we have a chance,
and we have been updating them when we run "git push" which already
breaks the original "predictability" anyway.

Now such a fetch does update refs/remotes/origin/master.

* jk/fetch-always-update-tracking:
  fetch: don't try to update unfetched tracking refs
  fetch: opportunistically update tracking refs
  refactor "ref->merge" flag
  fetch/pull doc: untangle meaning of bare <ref>
  t5510: start tracking-ref tests from a known state
Merge branch 'jc/strbuf-branchname-fix'

"git merge @{-1}~22" was rewritten to "git merge frotz@{1}~22"
incorrectly when your previous branch was "frotz" (it should be
rewritten to "git merge frotz~22" instead).

* jc/strbuf-branchname-fix:
  strbuf_branchname(): do not double-expand @{-1}~22
Merge branch 'rs/tar-tests'

* rs/tar-tests:
  t5000: test long filenames
  t5000: simplify tar-tree tests
  t5000: use check_tar for prefix test
  t5000: factor out check_tar
  t5000, t5003: create directories for extracted files lazily
  t5000: integrate export-subst tests into regular tests
Merge branch 'mc/describe-first-parent'

* mc/describe-first-parent:
  describe: Add --first-parent option
Merge branch 'tr/line-log'

* tr/line-log:
  git-log(1): remove --full-line-diff description
  line-log: fix documentation formatting
  log -L: improve comments in process_all_files()
  log -L: store the path instead of a diff_filespec
  log -L: test merge of parallel modify/rename
  t4211: pass -M to 'git log -M -L...' test
  log -L: fix overlapping input ranges
  log -L: check range set invariants when we look it up
  Speed up log -L... -M
  log -L: :pattern:file syntax to find by funcname
  Implement line-history search (git log -L)
  Export rewrite_parents() for 'log -L'
  Refactor parse_loc