sort: prudently make it subject to compat value

* eval.c (eval_init): If opt_compat is 237 or less, make sort
and shuffle destructive.

* share/txr/stdlib/getopts.tl (opthelp): Revert previous
change, restoring use of copy-list and use nsort instead of
sort, so the function is not affected by the 237 compatibility
being turned on.

* txr.1: Add compatibility notes.

1 files changed, 20 insertions, 0 deletions

diff --git a/txr.1 b/txr.1
index f33024ad..a1a21800 100644
--- a/txr.1
+++ b/txr.1
@@ -32632,6 +32632,13 @@ The behavior of
 .code sort
 is not specified for hashes whose contents do not conform to this convention.
 
+Note:
+.code nsort
+was introduced in \*(TX 238. Prior to that version,
+.code sort
+behaved like
+.codn nsort .
+
 .coNP Function @ grade
 .synb
 .mets (grade < sequence >> [ lessfun <> [ keyfun ]])
@@ -32719,6 +32726,13 @@ were made using
 .code copy
 and then that copy were shuffled in-place and returned.
 
+Note:
+.code nshuffle
+was introduced in \*(TX 238. Prior to that version,
+.code shuffle
+behaved like
+.codn nshuffle .
+
 .coNP Function @ sort-group
 .synb
 .mets (sort-group < sequence >> [ keyfun <> [ lessfun ]])
@@ -73404,6 +73418,12 @@ of these version values, the described behaviors are provided if
 is given an argument which is equal or lower. For instance
 .code "-C 103"
 selects the behaviors described below for version 105, but not those for 102.
+.IP 237
+Compatibility values of 237 or lower restore the destructive behavior of the
+.code sort
+and
+.code shuffle
+functions.
 .IP 234
 In \*(TX 234 and older versions, the exception throwing functions
 .code throw