This blog is updated daily.
A general description is here.
When tracing rematched S4 methods, ‘trace’ could insert a call ‘trace(.local, tracer=, exit=, ...)’ with improper ‘tracer’ and ‘exit’ components. Thanks to Hao Wang for the report (PR#18707).
Fix for ‘grid.pack(..., row.after=)’ (and ‘row.before’ and ‘col.after’ and ‘col.before’). Thanks to Athenkosi Nkonyeni for report.
‘trace’ with non-‘NULL’ ‘exit’ replaced rematched S4 method definitions with non-rematched ones that evaluated ‘exit’ twice, first on ‘.local’ exit and again on method exit.
In plain-text help (‘Rd2txt’), paragraphs are again recognized even when started with a non-indented Rd comment, fixing a regression in R 4.4.0.
‘rhyper(N, m, n, k)’ now switches to the “large” scenario when ‘m + n’ is larger than ‘.Machine$integer.max’, preventing integer overflow, thanks to Jonathan Blood's report on R-devel.
Fix long standing (Fortran compiler optimization related) bug in ‘nlminb’ with constraints, thanks to Kasper Kristensen's PR#19086 report and patch.
Fix for PR#19100: ‘seq.int’ was not handling non-vector ‘along.width’ arguments properly. Thanks to Mitchell O'Hara-Wild.
Wrappers now duplicate even a wrapped object that might be shared before returning a read-only pointer. This prevents cached read-only pointers from becoming invalid. Reported by Ivan Krylov.
‘dummy.coef()’ becomes more robust to non-syntactic variable names, fixing PR#18468. Thanks to Bill Dunlap and ‘R Dev Day’ participants Vincent Arel-Bundock, Cynthia Huang, Tina Rozsos and Marina Marinelli.
Now ‘PROTECT()’ in ‘SubassignTypeFix’, fixing PR#19110 thanks to Kevin Ushey.
‘writeChar()’ in a multibyte locale counts characters and bytes consistently and no longer overflows, thanks to Kevin Ushey's report and patch in PR#19112.
‘dim(a) <- vec’ now checks for too large ‘prod(vec)’, thanks to Kevin Ushey's report and patch in PR#19109.
Tweaks (including to the parsers) for the C23 behaviour (preserving ‘const’) of ‘strchr’, ‘strrchr’ and ‘strstr’. (By Brian Ripley and Duncan Murdoch.)
‘make check-devel’ now works without recommended packages.
‘<matrix>[[i, j]]’ with negative ‘i’ occasionally gives no error but accesses ‘previous content’; thanks to Kevin Ushey's report and very simple fix in PR#19116.
Quartz device now correctly draws long paths (work-around for Quartz built-in stroker breaking long paths). Thanks to R Dev Day @ useR! 2026 contributors, notably Tomek Gieorgijewski, report in PR#18680.
‘strptime(ch, "...%OS<n>...")’ now disregards contiguous digits in "<n>", for symmetry with ‘strftime()’, fulfilling Frederick Eaton's wish in PR#17209, thanks to a patch by Suharto Anggono.
‘strptime()’ now also returns ‘NA’ for out of range ‘"%OS"’ and a correct error message in some wrong multibyte cases, fixing PR#19117 comment #1 and PR#19122 by Michael Chirico; additionally, some overflow to ‘Inf’ times no longer result in ‘NA’.
‘strptime("0", "%w")’ in a ‘"C"’ locale now works in valid cases, returning ‘NA’ for invalid week numbers (‘"%U"’ or ‘"%W"’), fixing PR#19124 thanks to Michael Chirico's report and notably Suharto Anggono's analysis, also correctly fixing PR#15195.
‘ksmooth(x,y, x.points=NULL)’ now returns an empty (x,y) pair instead of crashing R, fixing PR#19153.
Additionally, also by Adam Berkeš, ‘x <- rep(999,0); ksmooth(x, x, x.points = 1)’ no longer writes out of bounds, fixing PR#19171. Ditto for ‘ksmooth(x, x, n.points = 0)’, PR#19219.
‘besselI(1, 1e11)’ and ‘besselK(..)’ now signal a warning and return ‘NaN’ instead of typically segfaulting, fixing PR#19175 thanks to Ben Bolker.
Further, ‘besselK(1, -1e11)’ and similar warn about too large ‘|nu|’, returning ‘NaN’ rather than segfaulting, fixing PR#19196 thanks to Adam Berkeš.
‘text.default(.., col = numeric(0))’ and similar no longer segfault in "instrumented" versions of R, fixing PR#19178 thanks to Jiang Yuancheng's ‘fusion-fuzz’ and Ivan Krylov.
‘R CMD rtags’ (on Unix-alikes) no longer fails from a bad escape if ‘sh’ is ‘bash’ or ‘busybox’.
‘capabilities("X11")’ no longer incorrectly returns ‘TRUE’ on a Unix-alike where X11 is not actually available when built by a C compiler without C23 ‘enum’ base types, thanks to Trevor Davis' report and patch in PR#19180.
‘predict(smooth.spline(..), deriv = -99)’ and similar invalid ‘deriv’ values now signal errors instead of segfaulting, thanks to Adam Berkeš' report and proposal in PR#19190.
‘format(x, width = 2^31 -1)’ for an non-ascii character ‘x’ such as ‘x = "\u00e9"’ now signals an error as the required width is too large, rather than segfaulting, thanks to Adam Berkeš' report in PR#19188.
‘influence.measures()’ inadvertently wasn't updated along with ‘dffits()’, ‘dfbetas()’, ‘covratio()’. PR#19167 by Amal Tawfik.
Long stringed error messages are now protected from premature garbage collection, fixing PR#19210, reported and analyzed by Yuancheng Jiang.
‘isoreg(numeric(0))’ no longer returns unallocated component ‘yc’, fixing PR#19224 thanks to Kevin Ushey.
‘KalmanLike(1:5, list(1,2))’ and similar no longer segfault, fixing PR#19217 thanks to Kevin Ushey and Adam Berkeš.
‘path.expand("~")’ and similar now should work correctly on Windows when the user name is not in ASCII and neither ‘%HOME%’ nor ‘%USER%’ environment variables are set, fixing PR#18949 thanks to the report and patch from Ivan Krylov and Mauricio Vargas's R Dev Day work.
‘file.copy(*, date=TRUE)’ no longer opens files for exclusive access when copying the file time. Consequently, the time _is_ copied now and concurrent attempts to open the source file should work reliably, thanks to Kevin Ushey's report and patch in PR#19187.