tree 2603122fa65878f32442d8faf35b1c82cc2cc87c
parent 10fb3f58da82d3538de0565eb2b797fbccecbba7
author Jonas Finnemann Jensen <jonasfj@google.com> 1597310440 +0200
committer GitHub <noreply@github.com> 1597310440 +0200
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Avoid O(2^N) complexity when reformating an incompatibility-tree of depth N. (#2615)

For incompatibilities with a `ConflictCause` the `reformatRanges` called itself
on each branch `ConflictCause.conflict` and `ConflictCause.other`.
Then it also `_reformatCause` which again calls `reformatRanges` for
each branch of a `ConflictCause`.

This means `reformatRanges` was called 2^N times for any node at depth N
in an `Incompatibility`-tree. Hence, a degenerate incompatibility tree
could effective cause `pub get` to hang, instead of printing an error
signaling a resolution conflict.

This bug has not affected `pub get` invocations where a resolution was
possible.