chainparams: sync the public dogecoin_chainparams with the internal one

CMakeLists.txt

@@ -553,6 +553,7 @@ IF(USE_TESTS)
         test/block_tests.c
         test/buffer_tests.c
         test/chacha20_tests.c
+        test/chainparams_abi_tests.c
         test/context_tests.c
         test/cstr_tests.c
         test/ecc_tests.c

Makefile.am

@@ -280,6 +280,7 @@ tests_SOURCES = \
     test/block_tests.c \
     test/buffer_tests.c \
     test/chacha20_tests.c \
+    test/chainparams_abi_tests.c \
     test/context_tests.c \
     test/cstr_tests.c \
     test/ecc_tests.c \

include/dogecoin/libdogecoin.h

@@ -45,6 +45,14 @@ typedef struct dogecoin_dns_seed_ {
     char domain[256];
 } dogecoin_dns_seed;
 
+/* Declared here and again in the internal chainparams.h, so that this header
+   stays self-contained. The objects are defined once, in chainparams.c, against
+   the internal copy and read through this one -- so the two must describe the
+   same layout, field for field and in order. A field added to one and not the
+   other shifts every field after it with no compile error and no warning; that
+   is what happened to genesisblockchainwork, which left consumers reading
+   default_port out of the middle of the chainwork. Change both, in step.
+   test/chainparams_abi_tests.c fails if they diverge again. */
 typedef struct dogecoin_chainparams_ {
     char chainname[32];
     uint8_t b58prefix_pubkey_address;
@@ -55,8 +63,13 @@ typedef struct dogecoin_chainparams_ {
     uint32_t b58prefix_bip32_pubkey;
     const unsigned char netmagic[4];
     uint256_t genesisblockhash;
+    uint256_t genesisblockchainwork;
     int default_port;
     dogecoin_dns_seed dnsseeds[8];
+    dogecoin_bool strict_id;
+    dogecoin_bool auxpow_id;
+    uint256_t pow_limit;
+    uint256_t minimumchainwork;
 } dogecoin_chainparams;
 
 typedef struct dogecoin_checkpoint_ {

test/chainparams_abi_tests.c

@@ -0,0 +1,107 @@
+/*
+
+ The MIT License (MIT)
+
+ Copyright (c) 2026 bluezr
+ Copyright (c) 2026 The Dogecoin Foundation
+
+ Permission is hereby granted, free of charge, to any person obtaining
+ a copy of this software and associated documentation files (the "Software"),
+ to deal in the Software without restriction, including without limitation
+ the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ and/or sell copies of the Software, and to permit persons to whom the
+ Software is furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included
+ in all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
+ OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+#include <stddef.h>
+
+#include <test/utest.h>
+
+/* libdogecoin.h is deliberately the only header this file includes.
+ *
+ * dogecoin_chainparams is declared twice by design -- once in the public
+ * libdogecoin.h, once in the internal chainparams.h -- so that the installed
+ * header stays self-contained and a consumer needs exactly one include. The
+ * objects (dogecoin_chainparams_main and friends) are defined once, in
+ * chainparams.c, against the internal declaration and read through the public
+ * one.
+ *
+ * The cost of two declarations is that they can drift, and they did: the public
+ * copy was missing genesisblockchainwork. That field sits in the middle rather
+ * than at the end, so it was not a harmless truncation -- every field after it
+ * landed 32 bytes early. A consumer reading default_port through the public
+ * header read at offset 84 while the object had it at 116, landing in the first
+ * four bytes of the chainwork. No compile error, no warning.
+ *
+ * Including both headers here to compare them is not possible: C forbids
+ * redefining a struct tag even identically. So this file does the next best
+ * thing and reads the exported objects exactly as a consumer does, through the
+ * public declaration alone. The values below agree only if that declaration
+ * describes the same layout chainparams.c was compiled with. Drift shifts the
+ * offsets and these comparisons fail. */
+#include <dogecoin/libdogecoin.h>
+
+void test_chainparams_abi()
+{
+    /* Fields before the divergence. If these fail the symbol itself is wrong,
+       not the layout. */
+    u_assert_str_eq(dogecoin_chainparams_main.chainname, "main");
+    u_assert_int_eq(dogecoin_chainparams_main.b58prefix_pubkey_address, 0x1e);
+    u_assert_int_eq(dogecoin_chainparams_main.b58prefix_secret_address, 0x9e);
+    u_assert_uint32_eq(dogecoin_chainparams_main.b58prefix_bip32_pubkey, 0x02facafd);
+
+    /* genesisblockchainwork, the field that was missing. Mainnet's is
+       0x00100010 in the low word, stored little-endian. Reading it proves the
+       public declaration has the field rather than skipping past it. */
+    u_assert_int_eq(dogecoin_chainparams_main.genesisblockchainwork[0], 0x10);
+    u_assert_int_eq(dogecoin_chainparams_main.genesisblockchainwork[2], 0x10);
+
+    /* The field immediately after it. This is the assertion the old layout
+       failed, and the one a consumer would have hit first. */
+    u_assert_int_eq(dogecoin_chainparams_main.default_port, 22556);
+    u_assert_int_eq(dogecoin_chainparams_test.default_port, 44556);
+    u_assert_int_eq(dogecoin_chainparams_regtest.default_port, 18332);
+
+    /* Further past the shift: the seed list moves by the same 32 bytes, so the
+       old layout read into the middle of a hostname. */
+    u_assert_str_eq(dogecoin_chainparams_main.dnsseeds[0].domain, "seed.multidoge.org");
+
+    /* Trailing fields the public header did not declare at all.
+
+       strict_id and auxpow_id are both typed dogecoin_bool, but only the first
+       is a boolean: auxpow_id carries the AuxPoW chain ID, 0x62 for Dogecoin on
+       every network. dogecoin_bool is a uint8_t, so a chain ID above 255 would
+       truncate silently. Dogecoin's does not, and retyping it is a separate
+       change -- asserted here as the value it actually holds, not as true. */
+    u_assert_int_eq(dogecoin_chainparams_main.strict_id, true);
+    u_assert_int_eq(dogecoin_chainparams_test.strict_id, false);
+    u_assert_int_eq(dogecoin_chainparams_main.auxpow_id, 0x62);
+    u_assert_int_eq(dogecoin_chainparams_regtest.auxpow_id, 0x62);
+
+    /* minimumchainwork, the last field in the struct, so reading it correctly
+       means the whole extent lines up. Deliberately not pow_limit: its byte
+       order is being changed under separate review, and this test should fail
+       on layout drift only. */
+    u_assert_int_eq(dogecoin_chainparams_main.minimumchainwork[0], 0x9b);
+    u_assert_int_eq(dogecoin_chainparams_main.minimumchainwork[1], 0xa4);
+    u_assert_int_eq(dogecoin_chainparams_regtest.minimumchainwork[0], 0x02);
+
+    /* Whole-struct size and the two offsets that moved. A consumer that
+       stack-allocates or copies a dogecoin_chainparams gets these wrong when the
+       declaration is short, and the damage is silent. */
+    u_assert_uint32_eq((uint32_t)sizeof(dogecoin_chainparams), 2236);
+    u_assert_uint32_eq((uint32_t)offsetof(dogecoin_chainparams, default_port), 116);
+    u_assert_uint32_eq((uint32_t)offsetof(dogecoin_chainparams, dnsseeds), 120);
+}

test/unittester.c

@@ -48,6 +48,7 @@ extern void test_bip44();
 extern void test_block_header();
 extern void test_buffer();
 extern void test_chacha20();
+extern void test_chainparams_abi();
 extern void test_cstr();
 extern void test_ecc();
 extern void test_hash();
@@ -179,6 +180,7 @@ int main()
     u_run_test(test_block_header);
     u_run_test(test_buffer);
     u_run_test(test_chacha20);
+    u_run_test(test_chainparams_abi);
     u_run_test(test_cstr);
     u_run_test(test_ecc);
     u_run_test(test_hash);