[PATCH 3/7] git.c: provide setup_auto_pager()
- From
- Martin Ågren <martin.agren@gmail.com>
- Date
- Jul 10, 2017, 21:55 UTC
- Message-ID
- <1d639a4c7be5f1c173502f79e85aadd017ef5f7c.1499723297.git.martin.agren@gmail.com>
- In-Reply-To
- <cover.1499723297.git.martin.agren@gmail.com>
The previous patch introduced a way for builtins to declare that they will take responsibility for handling the `pager.foo`-config item. (See the commit message of that patch for why that could be useful.)
Provide setup_auto_pager(), which builtins can call in order to handle `pager.<cmd>`, including possibly starting the pager. Make this function don't do anything if a pager has already been started.
When the `cmd` given to setup_auto_pager() contains one or more '.', use a fallback strategy which checks `pager.foo.bar.baz`, then `pager.foo.bar`, then `pager.foo`, then resorts to the provided default value. This ensures a consistent fallback strategy for builtins which take this type of more fine-grained pager configuration.
An alternative fallback strategy would have been to check for `pager.foo.bar.baz`, then immediately fall back to `def`. However, that would have meant that git foo would sometimes completely ignore `pager.foo`, which seems conceptually wrong. It would also have meant that builtins that are moved to more fine-grained pager configurations would have regressed for certain usecases.
Whenever this function is called from a builtin, git.c will already have called commit_pager_choice(). Since commit_pager_choice() treats the special value -1 as "punt" or "not yet decided", it is not a problem that we might end up calling commit_pager_choice() many times. Make the new function use -1 in the same way and document it as "punt".
Don't add any users of setup_auto_pager just yet, one will follow in later patches.
setup_auto_pager() is more capable than it needs to be for this patch series. It would have been sufficient to handle zero or one '.'. We would probably have wanted some verification+BUG()-patterns or to define whether we split at the first or last '.', so it seems just as easy, and certainly more flexible, to handle the more general situation.
Signed-off-by: Martin Ågren <martin.agren@gmail.com> --- builtin.h | 14 ++++++++++++++ git.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+)
diff --git a/builtin.h b/builtin.h index 498ac80d0..a6ed6c4ac 100644 --- a/builtin.h +++ b/builtin.h @@ -25,6 +25,20 @@ struct fmt_merge_msg_opts { extern int fmt_merge_msg(struct strbuf *in, struct strbuf *out, struct fmt_merge_msg_opts *); +/** + * If a builtin has IGNORE_PAGER_CONFIG set, the builtin should call this early + * when it wishes to respect the `pager.foo`-config. In the simplest case, the + * `cmd` is the name of the builtin, e.g., "foo". If a paging-choice has already + * been setup, this does nothing. The default in `def` should be 0 for "pager + * off", 1 for "pager on" or -1 for "punt". + * + * With one or more '.', substrings are tried out from longer to shorter. If no + * config is found, uses `def`. For example, with `cmd` as "foo.bar.baz", this + * function tries `pager.foo.bar.baz`, `pager.foo.bar` and `pager.foo` in that + * order before resorting to `def`. + */ +extern void setup_auto_pager(const char *cmd, int def); + extern int is_builtin(const char *s); extern int cmd_add(int argc, const char **argv, const char *prefix); diff --git a/git.c b/git.c index ae92f8ed5..696eaf87a 100644 --- a/git.c +++ b/git.c @@ -33,6 +33,34 @@ static void commit_pager_choice(void) { } } +void setup_auto_pager(const char *cmd, int def) +{ + if (use_pager != -1) + return; + + use_pager = check_pager_config(cmd); + + if (use_pager == -1) { + struct strbuf buf = STRBUF_INIT; + size_t len; + + strbuf_addstr(&buf, cmd); + len = buf.len; + while (use_pager == -1 && len--) { + if (buf.buf[len] == '.') { + strbuf_setlen(&buf, len); + use_pager = check_pager_config(buf.buf); + } + } + strbuf_release(&buf); + } + + if (use_pager == -1) + use_pager = def; + + commit_pager_choice(); +} + static int handle_options(const char ***argv, int *argc, int *envchanged) { const char **orig_argv = *argv;
-- 2.13.2.653.gfb5159d