The deprecated support for PCRE versions older than 8.20

code contained multi-byte characters.  (

no longer returns NA on Windows when the

file or directory is being used by another process.  This affected

return incorrect results when called with

extracting srcrefs from a file not encoded in the current locale.

has some additional protection for such files.

Non-UTF-8 multibyte character sets were not handled properly

URLs.  There will be small changes in the format and wording of

messages, including in rare cases if an issue is a warning or an

error.  For example, when HTTP re-direction occurs, some messages

refer to the final URL rather than the specified one.

Those who use proxies should check that their settings are

consistent and become back compatible to

method does resulting in less extraneous rounding, notably of

arrays now behave consistently, notably for arrays of length zero.

Arithmetic between length-1 arrays and longer non-arrays had

silently dropped the array attributes and recycled.  This now

gives a warning and will signal an error in the future, as it has

always for logic and comparison operations in these cases (e.g.,

enabled by default at its level 3. This means functions will be

compiled on first or second use and top-level loops will be

compiled and then run.  (Thanks to Tomas Kalibera for extensive

For now, the compiler will not compile code containing explicit

: this is to support single stepping from

JIT compilation can be disabled for the rest of the session using

appropriate.  Additionally, for the case

Matrix products now consistently bypass BLAS when the inputs

inputs has been improved. Performance when BLAS is used is

improved for matrix/vector and vector/matrix multiplication (DGEMV

One can now choose from alternative matrix product implementations

implementation is not optimized for speed but consistent in

precision with other summations in R (using

for best speed, but usually with undefined behavior for inputs

more conveniently debugging S3 and S4 methods.  (Based on a patch by