forked from 1b-agent/opencadstudio-upstream
Bug:
SETVAR LUPREC and SETVAR AUPREC stored any parseable i16 verbatim, and
the header value flows through UnitContext into the per-call
formatters, which applied only a lower bound (.max(0)) with no upper
bound: format_length and format_angle rendered {:.*} with the raw
precision. SETVAR LUPREC 30000 therefore made format_length emit
30003-character strings on every properties and annotation formatting
call - a ~30 KB allocation per formatted value - while format_area in
the same file had long since capped itself with .min(15) and the units
dialog only ever offers 0-8 places. Negative values were also stored
verbatim.
Reproduce:
1. Command line: SETVAR LUPREC 30000 (or AUPREC 30000), then select
something so the properties palette formats lengths/angles.
2. Before: the header stores 30000 and each formatted value is ~30 KB
(the test measured 30003 chars for one length); -3 is stored as-is.
3. After: the setter stores 8 (0-8 range, echoed truthfully), -3
stores 0, 5 stores 5 - and even a file carrying LUPREC 30000 in its
header formats short output, because the formatters cap themselves.
Fix:
Two layers. The formatters get the cap format_area already uses:
format_signed_length and format_signed_angle now clamp with
.max(0).min(15), so every source - SETVAR, the units dialog, and
values carried in DWG/DXF files - produces bounded output on the hot
paths (15 matches the point past which f64 decimal output is
meaningless, which is why format_area was written that way). The
setters store x.clamp(0, 8) with the clamped value echoed back, the
same stay-inside-the-app's-own-UI-range rule SETVAR ISOLINES follows
against the Options slider. Architectural and fractional formats
ignore precision (fixed 1/64-inch resolution) and are unaffected.
Regression tests mirror the existing patterns: one forces hostile
precision through the formatters while saving and restoring the
thread-local unit context, one drives SETVAR through the command line
and checks the stored header values.