Rewrite conversion of double to int in xmlXPathSubstringFunction, adding
range checks to avoid undefined behavior. Make sure to add start and
length as floating-point numbers before converting to int. Fix a bug
when rounding negative start indices.
Remove unneeded calls to xmlXPathIs{Inf,NaN} and rely on IEEE math
instead. Avoid computing the string length. xmlUTF8Strsub works as
expected if the length of the requested substring exceeds the input.
Found with libFuzzer and UBSan.
* xpath.c: another patch from Richard Jinks for substring conformance
* test/XPath/expr/floats test/XPath/expr/strings
result/XPath/expr/floats result/XPath/expr/strings: update of the
test suite to check those.
Daniel
* trionan.c trionan.h xpath.c: more patches from Richard Jinks
* test/XPath/expr/compare test/XPath/expr/equality
test/XPath/expr/floats test/XPath/expr/functions
test/XPath/expr/strings result/XPath/expr/compare
result/XPath/expr/equality result/XPath/expr/floats
result/XPath/expr/functions result/XPath/expr/strings: Updated
tests though they show a divergence on Linux
Daniel
