tests: use "env" to run commands with temporary env-var settings

Ordinarily, we would say "VAR=VAL command" to execute a tested
command with environment variable(s) set only for that command.
This however does not work if 'command' is a shell function (most
notably 'test_must_fail'); the result of the assignment is retained
and affects later commands.

To avoid this, we used to assign and export environment variables
and run such a test in a subshell, like so:

        (
                VAR=VAL && export VAR &&
                test_must_fail git command to be tested
        )

But with "env" utility, we should be able to say:

        test_must_fail env VAR=VAL git command to be tested

which is much shorter and easier to read.

Signed-off-by: David Tran <unsignedzero@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fsck: use bitwise-or assignment operator to set flag

fsck_tree() has two different ways to set a flag variable, either by
using a if-statement that guards an assignment, or by using a
bitwise-or assignment operator.  Most are done with the former, and
only one variable is assigned with the latter.

Since all the conditions are short-and-sweet, we can afford to
uniformly use the latter style, which makes the resulting code
shorter and easier to read.

Signed-off-by: Hiroyuki Sano <sh19910711@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tree-diff: don't assume compare_tree_entry() returns -1,0,1

It does, but we'll be reworking it in the next patch after it won't, and
besides it is better to stick to standard
strcmp/memcmp/base_name_compare/etc... convention, where comparison
function returns <0, =0, >0

Regarding performance, comparing for <0, =0, >0 should be a little bit
faster, than switch, because it is just 1 test-without-immediate
instruction and then up to 3 conditional branches, and in switch you
have up to 3 tests with immediate and up to 3 conditional branches.

No worry, that update_tree_entry(t2) is duplicated for =0 and >0 - it
will be good after we'll be adding support for multiparent walker and
will stay that way.

=0 case goes first, because it happens more often in real diffs - i.e.
paths are the same.

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tree-diff: move all action-taking code out of compare_tree_entry()

- let it do only comparison.

This way the code is cleaner and more structured - cmp function only
compares, and the driver takes action based on comparison result.

There should be no change in performance, as effectively, we just move
if series from on place into another, and merge it to was-already-there
same switch/if, so the result is maybe a little bit faster.

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tree-diff: rename compare_tree_entry -> tree_entry_pathcmp

Since previous commit, this function does not compare entry hashes, and
mode are compared fully outside of it. So what it does is compare entry
names and DIR bit in modes. Reflect this in its name.

Add documentation stating the semantics, and move the note about
files/dirs comparison to it.

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tree-diff: show_path prototype is not needed anymore

We moved all action-taking code below show_path() in recent HEAD~~
(tree-diff: move all action-taking code out of compare_tree_entry).

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tree-diff: simplify tree_entry_pathcmp

Since an earlier "Finally switch over tree descriptors to contain a
pre-parsed entry", we can safely access all tree_desc->entry fields
directly instead of first "extracting" them through
tree_entry_extract.

Use it. The code generated stays the same - only it now visually looks
cleaner.

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
doc: status, remove leftover statement about '#' prefix

This hasn't been true since 2556b996 (status: disable display of '#'
comment prefix by default, 2013-09-06).

Signed-off-by: Dirk Wallenstein <halsmit@t-online.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
config.txt: third-party tools may and do use their own variables

Signed-off-by: Chris Angelico <rosuav@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
userdiff: support C++ ->* and .* operators in the word regexp

The character sequences ->* and .* are valid C++ operators. Keep them
together in --word-diff mode.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
userdiff: support unsigned and long long suffixes of integer constants

Do not split constants such as 123U, 456ll, 789UL at the first U or
second L.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4018: an infrastructure to test hunk headers

Add an infrastructure that simplifies adding new tests of the hunk
header regular expressions.

To add new tests, a file with the syntax to test can be dropped in the
directory t4018. The README file explains how a test file must contain;
the README itself tests the default behavior.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4018: convert perl pattern tests to the new infrastructure

There is one subtlety: The old test case 'perl pattern gets full line of
POD header' does not have its own new test case, but the feature is
tested nevertheless by placing the RIGHT tag at the end of the expected
hunk header in t4018/perl-skip-sub-in-pod.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4018: convert java pattern test to the new infrastructure

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4018: convert custom pattern test to the new infrastructure

For the test case "matches to end of line", extend the pattern by a few
wildcards so that the pattern captures the "RIGHT" token, which is needed
for verification, without mentioning it in the pattern.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4018: reduce test files for pattern compilation tests

All test cases that need a file with specific text patterns have been
converted to utilize texts in the t4018/ directory. The remaining tests
in the test script deal only with the validity of the regular
expressions. These tests do not depend on the contents of files that
'git diff' is invoked on. Remove the largish here-document and use only
tiny files.

While we are touching these tests, convert grep to test_i18ngrep as the
texts checked for may undergo translation in the future.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4018: test cases for the built-in cpp pattern

A later patch changes the built-in cpp pattern. These test cases
demonstrate aspects of the pattern that we do not want to change.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4018: test cases showing that the cpp pattern misses many anchor points

Most of the tests show C++ code, but there is also a union definition and
a GNU style function definition that are not recognized.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
userdiff: have 'cpp' hunk header pattern catch more C++ anchor points

The hunk header pattern 'cpp' is intended for C and C++ source code, but
it is actually not particularly useful for the latter, and even misses
some use-cases for the former.

The parts of the pattern have the following flaws:

- The first part matches an identifier followed immediately by a colon
  and arbitrary text and is intended to reject goto labels and C++
  access specifiers (public, private, protected). But this pattern also
  rejects C++ constructs, which look like this:

    MyClass::MyClass()
    MyClass::~MyClass()
    MyClass::Item MyClass::Find(...

- The second part matches an identifier followed by a list of qualified
  names (i.e. identifiers separated by the C++ scope operator '::')
  separated by space or '*' followed by an opening parenthesis (with
  space between the tokens). It matches function declarations like

    struct item* get_head(...
    int Outer::Inner::Func(...

  Since the pattern requires at least two identifiers, GNU-style
  function definitions are ignored:

    void
    func(...

  Moreover, since the pattern does not allow punctuation other than '*',
  the following C++ constructs are not recognized:

  . template definitions:
      template<class T> int func(T arg)

  . functions returning references:
      const string& get_message()

  . functions returning templated types:
      vector<int> foo()

  . operator definitions:
      Value operator+(Value l, Value r)

- The third part of the pattern finally matches compound definitions.
  But it forgets about unions and namespaces, and also skips single-line
  definitions

    struct random_iterator_tag {};

  because no semicolon can occur on the line.

Change the first pattern to require a colon at the end of the line
(except for trailing space and comments), so that it does not reject
constructor or destructor definitions.

Notice that all interesting anchor points begin with an identifier or
keyword. But since there is a large variety of syntactical constructs
after the first "word", the simplest is to require only this word and
accept everything else. Therefore, this boils down to a line that begins
with a letter or underscore (optionally preceded by the C++ scope
operator '::' to accept functions returning a type anchored at the
global namespace). Replace the second and third part by a single pattern
that picks such a line.

This has the following desirable consequence:

- All constructs mentioned above are recognized.

and the following likely desirable consequences:

- Definitions of global variables and typedefs are recognized:

    int num_entries = 0;
    extern const char* help_text;
    typedef basic_string<wchar_t> wstring;

- Commonly used marco-ized boilerplate code is recognized:

    BEGIN_MESSAGE_MAP(CCanvas,CWnd)
    Q_DECLARE_METATYPE(MyStruct)
    PATTERNS("tex",...)

  (The last one is from this very patch.)

but also the following possibly undesirable consequence:

- When a label is not on a line by itself (except for a comment) it is
  no longer rejected, but can appear as a hunk header if it occurs at
  the beginning of a line:

    next:;

IMO, the benefits of the change outweigh the (possible) regressions by a
large margin.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Makefile: describe CHARSET_LIB better

The original explanation was not even grammatically correct or
readable.

Signed-off-by: Junio C Hamano <gitster@pobox.com>