Fix undefined behavior in ncr() when casting NaN/Inf to unsigned int #135
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Fix undefined behavior in ncr() when converting NaN/Inf to unsigned int
While testing tinyexpr with UBSan (-fsanitize=undefined),
I encountered undefined behavior when NaN values were cast
to unsigned int in ncr().
The issue occurs when expressions evaluate to NaN or Inf,
which then reach ncr() and are converted to unsigned types.
According to the C standard, this conversion is undefined behavior.
This patch adds a guard using isfinite() before casting
to prevent undefined behavior.
Tested with:
clang -fsanitize=undefined -g example.c tinyexpr.c -o example
Ubuntu 22.04