PHP: Fixed exponential runtime of a pattern #2157
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Can we add a test to cover this scenario? |
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I didn't because the code is syntactically invalid which caused the exponential run time in the first place. |
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Can we add a test with the invalid code and ensure it completes? Even if the token stream is an empty array, it will still verify the bug is fixed (and not potentially reintroduced). |
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Added the test. It's parsed as an XML prolog. |
mAAdhaTTah
approved these changes
Jan 5, 2020
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This fixes the exponential runtime of the pattern used to identify PHP code embedded in HTML. (This resolves #2156.)
The problem was that the alternative for single-line comments
(?:\/\/|#)(?:[^?\n\r]|\?(?!>))*was open-ended, so the regex engine could decide how many characters to match. The fix is that I added a lookahead which enforces that these comments end at either the end of a line of the end of the PHP code block.