This PR was squashed before being merged into the 1.x branch.
Discussion
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In |filter(), |map(), and |reduce(), throw a RuntimeError instead of a TypeError
If a template accidentally performs `|filter(...)` on a variable that isn't traversable (e.g. `null`), the calling code will encouter the raw `TypeError` that results from Twig trying to construct an `IteratorIterator` on that variable. This means that context information (e.g., in which exact template the error occurred, and on which line) is discarded, which makes it very difficult to debug your templates.
This commit adds code to throw a `RuntimeError` if Twig encounters a situation where there's no valid way to filter an array.
Commits
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567b1e2a In |filter(), |map(), and |reduce(), throw a RuntimeError instead of a TypeError
Fabien Potencier
Thijs van Dijk
Jérémy Derussé