The current behavior of the functions 'calc-display-strings',
'strings', and 'bstrings' is to skip any vector containing
integers outside the Latin-1 range (0x00-0xFF). We introduce a
custom variable 'calc-string-maximum-character' to replace this
hard-coded maximum, and to allow vectors containing higher
character codes to be displayed as strings. The default value
of 0xFF preserves the existing behavior.
* lisp/calc/calc.el (calc-string-maximum-character): Add custom
variable 'calc-string-maximum-character'.
* lisp/calc/calccomp.el (math-vector-is-string): Replace hard-coded
maximum with 'calc-string-maximum-character', and the 'natnump'
assertion with 'characterp'. The latter guards against the
maximum being larger than '(max-char)', but not on invalid types of
the maximum such as strings.
* test/lisp/calc/calc-tests.el (calc-math-vector-is-string): Add
tests for 'math-vector-is-string' using different values of
'calc-string-maximum-character'.
* doc/misc/calc.texi (Quick Calculator, Strings, Customizing Calc):
Add variable definition for 'calc-string-maximum-character' and
reference thereof when discussing 'calc-display-strings'.
Generalize a comment about string display and availability of 8-bit
fonts.
(Bug#78528)