From 1cf3837c18abc74eb860db14a6f458d64d7c0ecc Mon Sep 17 00:00:00 2001
From: fhgffy <102001626+fhgffy@users.noreply.github.com>
Date: Sun, 4 Oct 2026 03:47:03 -0400
Subject: [PATCH] Preserve explicit 64-bit suffixes when parsing nondecimal
 integers

---
 lib/util.c                      |  4 ++-
 tests/testdata/int64-suffix.cfg |  3 ++
 tests/testdata/int64-suffix.txt |  3 ++
 tests/tests.c                   | 51 +++++++++++++++++++++++++++++++++
 4 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 tests/testdata/int64-suffix.cfg
 create mode 100644 tests/testdata/int64-suffix.txt

diff --git a/lib/util.c b/lib/util.c
index 8e1e82d..c30b3b6 100644
--- a/lib/util.c
+++ b/lib/util.c
@@ -123,7 +123,9 @@ int libconfig_parse_integer(const char *s, int base, long long *val,
   errno = 0;
   *val = strtoll(s, &endptr, base);
 
-  if((base != 10) && (*val > INT32_MAX) && (*val <= UINT32_MAX))
+  /* Only unsuffixed non-decimal values use 32-bit signed interpretation. */
+  if((base != 10) && (*endptr != 'L')
+     && (*val > INT32_MAX) && (*val <= UINT32_MAX))
     *val = (long long)(int)*val;
 
   *is_long = ((*val < INT32_MIN) || (*val > INT32_MAX));
diff --git a/tests/testdata/int64-suffix.cfg b/tests/testdata/int64-suffix.cfg
new file mode 100644
index 0000000..14b5178
--- /dev/null
+++ b/tests/testdata/int64-suffix.cfg
@@ -0,0 +1,3 @@
+hex = 0xFFFFFFFFL;
+binary = 0b11111111111111111111111111111111L;
+octal = 0o37777777777L;
diff --git a/tests/testdata/int64-suffix.txt b/tests/testdata/int64-suffix.txt
new file mode 100644
index 0000000..5bd50c1
--- /dev/null
+++ b/tests/testdata/int64-suffix.txt
@@ -0,0 +1,3 @@
+hex = 0xFFFFFFFFL;
+binary = 0b11111111111111111111111111111111L;
+octal = 4294967295L;
diff --git a/tests/tests.c b/tests/tests.c
index 85fa430..0b71890 100644
--- a/tests/tests.c
+++ b/tests/tests.c
@@ -760,6 +760,56 @@ TT_TEST(BinaryAndHex)
 
 /* ------------------------------------------------------------------------- */
 
+TT_TEST(NonDecimalInt64Suffix)
+{
+  static const struct
+  {
+    const char *text;
+    long long value;
+    int type;
+  } cases[] = {
+    { "v = 0x7FFFFFFFL;", 2147483647LL, CONFIG_TYPE_INT64 },
+    { "v = 0x80000000L;", 2147483648LL, CONFIG_TYPE_INT64 },
+    { "v = 0xFFFFFFFFLL;", 4294967295LL, CONFIG_TYPE_INT64 },
+    { "v = 0x100000000L;", 4294967296LL, CONFIG_TYPE_INT64 },
+    { "v = 0b10000000000000000000000000000000L;", 2147483648LL,
+      CONFIG_TYPE_INT64 },
+    { "v = 0b11111111111111111111111111111111LL;", 4294967295LL,
+      CONFIG_TYPE_INT64 },
+    { "v = 0o20000000000L;", 2147483648LL, CONFIG_TYPE_INT64 },
+    { "v = 0q37777777777LL;", 4294967295LL, CONFIG_TYPE_INT64 },
+    { "v = 0xFFFFFFFF;", -1LL, CONFIG_TYPE_INT },
+    { "v = 0b11111111111111111111111111111111;", -1LL, CONFIG_TYPE_INT },
+    { "v = 0o37777777777;", -1LL, CONFIG_TYPE_INT },
+    { "v = 4294967295L;", 4294967295LL, CONFIG_TYPE_INT64 },
+    { "v = -2147483649L;", -2147483649LL, CONFIG_TYPE_INT64 },
+    { "v = 0x7FFFFFFFFFFFFFFFL;", 9223372036854775807LL,
+      CONFIG_TYPE_INT64 }
+  };
+  unsigned int i;
+
+  for(i = 0; i < sizeof(cases) / sizeof(cases[0]); ++i)
+  {
+    config_t cfg;
+    config_setting_t *setting;
+    config_init(&cfg);
+    TT_ASSERT_TRUE(config_read_string(&cfg, cases[i].text));
+    setting = config_lookup(&cfg, "v");
+    TT_ASSERT_PTR_NE(setting, NULL);
+    if(setting)
+    {
+      TT_ASSERT_INT_EQ(config_setting_type(setting), cases[i].type);
+      TT_ASSERT_INT64_EQ(config_setting_get_int64(setting), cases[i].value);
+    }
+    config_destroy(&cfg);
+  }
+
+  parse_and_compare("./testdata/int64-suffix.cfg",
+                    "./testdata/int64-suffix.txt");
+}
+
+/* ------------------------------------------------------------------------- */
+
 int main(int argc, char **argv)
 {
   int failures;
@@ -782,6 +832,7 @@ int main(int argc, char **argv)
   TT_SUITE_TEST(LibConfigTests, IncludeReadError);
   TT_SUITE_TEST(LibConfigTests, ReadStream);
   TT_SUITE_TEST(LibConfigTests, BinaryAndHex);
+  TT_SUITE_TEST(LibConfigTests, NonDecimalInt64Suffix);
   TT_SUITE_RUN(LibConfigTests);
   failures = TT_SUITE_NUM_FAILURES(LibConfigTests);
   TT_SUITE_END(LibConfigTests);