Fix error state when setting existing language after non-existing

[mermshaus]

See GeSHi::set_language for reference.

$geshi->set_language('php');
    // $this->loaded_language is "...php.php"
$geshi->set_language('does-not-exist');
    // $this->loaded_language is still "...php.php"
    // $this->error is set to GESHI_ERROR_NO_SUCH_LANG
$geshi->set_language('php');
    // $this->loaded_language is still "...php.php"
    // and $this->error won't be reset to false because the line is below
    // if ($file_name == $this->loaded_language) { return; }

Because of the error state, no syntax highlighting for 'php' will take place until you do a hard reset via $geshi->set_language('php', true); or via $geshi->error = false; or until you load a different existing language.

GeSHi::parse_code:

        // Firstly, if there is an error, we won't highlight
        if ($this->error) {
            // ...
            return $result;
        }

I don’t suppose this is intentional.

This request contains one quick idea to fix this. It might not be a good one. For instance, I did not check the implications of moving $this->strict_mode = GESHI_NEVER;.

In any case, don’t feel obliged to merge. This is meant as a heads up.

Best

[BenBE]

Hmmm, I'm not sure yet if the behaviour really is broken here for two reasons:

1. It's kinda intensional as an optimization that it doesn't realod a language if this one is already loaded
2. If there's an error when adding a language (without the second parameter true) than doing so from an error state still is an error.

But yet I see your point. Will think about it.

[mermshaus]

Here’s a complete example. The output for example 3 demonstrates the issue.

<?php

include __DIR__ . '/src/geshi.php';

$geshi = new GeSHi();

$geshi->set_language('php');
$geshi->set_source('<?php echo "Hello world!"');
echo '#1 ' . substr($geshi->parse_code(), 0, 45) . "\n";

$geshi->set_language('does-not-exist');
$geshi->set_source('Hello world!');
echo '#2 ' . substr($geshi->parse_code(), 0, 45) . "\n";

$geshi->set_language('php');
$geshi->set_source('<?php echo "Hello world!"');
echo '#3 ' . substr($geshi->parse_code(), 0, 45) . "\n";

$geshi->set_language('php', true); // <-- note the true
$geshi->set_source('<?php echo "Hello world!"');
echo '#4 ' . substr($geshi->parse_code(), 0, 45) . "\n";

// Output:
// #1 <pre class="php" style="font-family:monospace
// #2 <pre class="does-not-exist" style="font-famil
// #3 <pre class="does-not-exist" style="font-famil
// #4 <pre class="php" style="font-family:monospace

There are some inconsistencies in the handling of the involved state variables.

[cweiske]

It's in master now, given that it at least improves the current situation - even if it's not perfect.