[PATCH v5 0/7] grep: simplify & delete "init" & "config" code

A simplification and code deletion of the overly complex setup for the grep API, no behavior changes. For v4 see: https://lore.kernel.org/git/cover-v4-0.7-00000000000-20211203T101348Z-avarab@gmail.com/

This re-roll is rebased on the latest push-out to "master", now-landed topic had a minor conflict with it in git.c.

Ævar Arnfjörð Bjarmason (7):
  grep.h: remove unused "regex_t regexp" from grep_opt
  log tests: check if grep_config() is called by "log"-like cmds
  grep tests: add missing "grep.patternType" config test
  built-ins: trust the "prefix" from run_builtin()
  grep.c: don't pass along NULL callback value
  grep API: call grep_config() after grep_init()
  grep: simplify config parsing and option parsing

 builtin/grep.c    |  27 +++++-----
 builtin/log.c     |  13 ++++-
 builtin/ls-tree.c |   2 +-
 git.c             |   1 +
 grep.c            | 124 ++++++++--------------------------------------
 grep.h            |  33 ++++++++----
 revision.c        |   4 +-
 t/t4202-log.sh    |  24 +++++++++
 t/t7810-grep.sh   |  19 +++++++
 9 files changed, 116 insertions(+), 131 deletions(-)

Range-diff against v4:
1:  d7d232b2b52 = 1:  b6a3e0e2e08 grep.h: remove unused "regex_t regexp" from grep_opt
2:  f853d669682 = 2:  c0d77b2683f log tests: check if grep_config() is called by "log"-like cmds
3:  a97b7de3a3c = 3:  f02f246aa23 grep tests: add missing "grep.patternType" config test
4:  f7d995a5a80 ! 4:  a542a352eab built-ins: trust the "prefix" from run_builtin()
    @@ builtin/ls-tree.c: int cmd_ls_tree(int argc, const char **argv, const char *pref
     
      ## git.c ##
     @@ git.c: static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
    - 			int nongit_ok;
    - 			prefix = setup_git_directory_gently(&nongit_ok);
    - 		}
    -+		assert(!prefix || *prefix);
    - 		precompose_argv_prefix(argc, argv, NULL);
    - 		if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
    - 		    !(p->option & DELAY_PAGER_CONFIG))
    + 	} else {
    + 		prefix = NULL;
    + 	}
    ++	assert(!prefix || *prefix);
    + 	precompose_argv_prefix(argc, argv, NULL);
    + 	if (use_pager == -1 && run_setup &&
    + 		!(p->option & DELAY_PAGER_CONFIG))
     
      ## grep.c ##
     @@ grep.c: int grep_config(const char *var, const char *value, void *cb)
5:  ab1685f0dad = 5:  a33b00a247e grep.c: don't pass along NULL callback value
6:  8ffa22df8c7 = 6:  92b1c3958fa grep API: call grep_config() after grep_init()
7:  efbd1c50b43 = 7:  63de643ebc2 grep: simplify config parsing and option parsing