[w4ffl35]

On 32-bit platforms size_t is 32 bits: escape_characters += 5 wraps past ~858M control characters (5 * 858993460 = 2^32 + 4), and the length sums can wrap too, so ensure() is asked for a small buffer while the write loop emits the true escaped length -- heap overflow, reachable via cJSON_PrintBuffered with a pre-allocated buffer.

This fails instead of wrapping at each accumulation step and before sizing the allocation, using (size_t)-1 so no new headers are needed. On 64-bit the guards are inert (verified: full suite green, escape-heavy output byte-exact).

Evidence:

• Reproducer: 200KB control-char string prints byte-exact (1200002 chars); uint32_t simulation of the exact counter expressions proves the pre-fix wrap (counter lands on 4) and the post-fix guard trip. A 32-bit trigger needs ~859MB of control characters, not feasible on this 64-bit host -- the arithmetic proof plus inspection stands in for execution there. Full ctest suite passes (19/19).
• Adds print_string_should_print_escape_heavy_strings_exactly to tests/print_string.c.