pack-objects: widen delta-cache accounting to `size_t`

These three are a single accounting tuple (the globals tracking
cumulative cached-delta bytes, plus the helper that compares them
against an incoming delta size) and are latently 32-bit on Windows where
`unsigned long` != `size_t`: a pack with many large cached deltas could
wrap silently.

The widening is internally consistent on its own: the additions and
subtractions against delta_cache_size already come from `size_t` sources
(`DELTA_SIZE()` returns `size_t`), and `delta_cacheable()`'s sole caller
in `try_delta()` still passes `unsigned long`, which promotes.

Prerequisite for dropping `try_delta()`'s `cast_size_t_to_ulong()`
shims, which becomes possible once 1create_delta()` and `diff_delta()`
are widened in a later commit.

Assisted-by: Opus 4.7
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 27048bbb4dd3c9507fd1641658d30e16599caff4..2c525cc1b2948ce18ffdd5b1178012cb527fe25b 100644 (file)
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -260,8 +260,8 @@ static int exclude_promisor_objects_best_effort;
 
 static int use_delta_islands;
 
-static unsigned long delta_cache_size = 0;
-static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
+static size_t delta_cache_size = 0;
+static size_t max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
 static unsigned long cache_max_small_delta_size = 1000;
 
 static unsigned long window_memory_limit = 0;
@@ -2687,8 +2687,8 @@ struct unpacked {
        unsigned depth;
 };
 
-static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
-                          unsigned long delta_size)
+static int delta_cacheable(size_t src_size, size_t trg_size,
+                          size_t delta_size)
 {
        if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
                return 0;