common: Do not crash on PHP startup error

F3 crashes when there were PHP startups error even though
they might not affect the program (e.g. unable to load an extension).
It also sets its own error_reporting value and uses the previous one
as a signal to disable the initialization failure check.

Let's use that to avoid the crash and log the error ourselves.

Fixes: #1192

NEWS.md

@@ -78,6 +78,7 @@
 - RSS spout now prefers the feed logo to website favicon. ([#1152](https://github.com/SSilence/selfoss/pull/1152))
 - RSS spout now tries to use favicon from the feed domain when there is no logo or home page favicon. ([#1152](https://github.com/SSilence/selfoss/pull/1152))
 - Setting `DEBUG` to `1` in `src/common.php` no longer logs HTTP bodies, only headers. Set it to `2` if you need the bodies as well. ([#1152](https://github.com/SSilence/selfoss/pull/1152))
+- PHP startup errors are now logged, instead of having F3 crash with Error 500 ([#1195](https://github.com/SSilence/selfoss/pull/1195))
 
 
 ## 2.18 – 2018-03-05

src/common.php

@@ -15,6 +15,14 @@
     exit;
 }
 
+$startup_error = error_get_last();
+
+// F3 crashes when there were PHP startups error even though
+// they might not affect the program (e.g. unable to load an extension).
+// It also sets its own error_reporting value and uses the previous one
+// as a signal to disable the initialization failure check.
+error_reporting(0);
+
 $f3 = Base::instance();
 
 $f3->set('DEBUG', 0);
@@ -186,6 +194,10 @@
 }
 $log->pushHandler($handler);
 
+if (isset($startup_error)) {
+    $log->warn('PHP likely encountered a startup error: ', [$startup_error]);
+}
+
 // init error handling
 $f3->set('ONERROR',
     function(Base $f3) use ($log, $handler) {