fix: keep the sign of negative JSON floats with a zero integer part

[edubraqd]

Problem

JsonParse-Float loses the sign of any JSON number in the open interval (-1, 0). The result comes back positive:

input	before	after
-0.5	+0.5	-0.5
-0.0009	+0.0009	-0.0009
-0.5e1	+5.0	-5.0
-1.5	-1.5	-1.5 (unaffected)

Root cause

The fractional multiplier's sign was taken from the parsed integer part:

IF LK-VALUE < 0
    MOVE -0.1 TO MULTIPLIER
ELSE
    MOVE 0.1 TO MULTIPLIER
END-IF

For -0.5 the integer part is 0, and JsonParse-Integer returns 0 (it captures the - sign but multiplies it by a zero magnitude). So LK-VALUE < 0 is false, the multiplier stays positive, and the sign is dropped. Values like -1.5 work only because their integer magnitude is non-zero.

Fix

Detect the - sign directly from the input before parsing, and use that flag to drive the fractional multiplier. The peek uses a separate offset and the same whitespace-skipping the integer parser already does, so it does not consume input or change the parse position.

Tests

Added three regression cases to Test-JsonParse-Float: -0.5, -0.0009, and -0.5e1. Full suite: 315 run, 0 failed.

make test
...
Tests run: 315
Tests failed: 0
Tests skipped: 6

🤖 Generated with Claude Code