Disable sqlite3 and pdo_sqlite by default

[cmb69]

Since libsqlite has been unbundled[1], it makes sense to change the
defaults of building ext/sqlite3 and ext/pdo_sqlite, i.e. to disable
both extensions by default – this is more in line with other bundled
extension which rely on external dependencies.

Nothing has to be done for Windows, since both extensions are disabled
by default already.

[1] http://git.php.net/?p=php-src.git;a=commit;h=6083a387a81dbbd66d6316a3a12a63f06d5f7109

[cmb69]

This issue has been pointed out by @sgolemon. Thanks!

I'm not sure whether the Travis configuration would have to be adjusted to still build the extensions and run the respective tests.

[Majkl578]

This sort of breaks the assumptions that SQLite is always available by default. A lot of projects use SQLite as a fallback/default database backend.

Also according to docs:

The SQLite3 extension is enabled by default as of PHP 5.3.0. It's possible to disable it by using --without-sqlite3 at compile time. [1]

The PDO_SQLITE PDO driver is enabled by default. [2]

[1] http://php.net/manual/en/sqlite3.installation.php
[2] http://php.net/pdo_sqlite

[cmb69]

@Majkl578 I'm not totally happy about this change, but what if there's no libsqlite3 available on the system?

[Ocramius]

This doesn't look like a good idea: yes, SQLite may not exist on the target system, in which case the build will fail, and that's OK.

[Majkl578]

but what if there's no libsqlite3 available on the system

That's probably something that should've been considered before unbundling SQLite, but not as a reason to disable it by default.

SQLite may not exist on the target system, in which case the build will fail, and that's OK.

Yes, and in this case they can still use --without-sqlite3/ --without-pdo-sqlite. 👍

[nikic]

IIRC we also require libxml2 in a default build, so there's precedent here.

On the other hand, IMHO you should not draw any conclusions of availability based on the "default" build. Unless it's part of --disable-all builds, the extension is optional and you can't rely on it being available. Distros are going to split the extension off anyway (php7.2-sqlite3), so de facto it's non-default anyway.

[cmb69]

IIRC we also require libxml2 in a default build, so there's precedent here.

Indeed. Thanks! So I tend to withdraw this PR, but I'll keep it open for while – maybe there are still good reasons to change the defaults.

[cmb69]

Okay, no further input – closing.