wallet: Add BerkeleyDB version sanity check at init time

Detect version conflicts between the run-time BerkeleyDB library and the one used during compilation.

This is very unsafe (can result in anything from crashes to corruption) so shut down when one is detected.

src/wallet/bdb.cpp

@@ -723,6 +723,23 @@ bool BerkeleyBatch::TxnAbort()
     return (ret == 0);
 }
 
+bool BerkeleyDatabaseSanityCheck()
+{
+    int major, minor;
+    DbEnv::version(&major, &minor, nullptr);
+
+    /* If the major version differs, or the minor version of library is *older*
+     * than the header that was compiled against, flag an error.
+     */
+    if (major != DB_VERSION_MAJOR || minor < DB_VERSION_MINOR) {
+        LogPrintf("BerkeleyDB database version conflict: header version is %d.%d, library version is %d.%d\n",
+            DB_VERSION_MAJOR, DB_VERSION_MINOR, major, minor);
+        return false;
+    }
+
+    return true;
+}
+
 std::string BerkeleyDatabaseVersion()
 {
     return DbEnv::version(nullptr, nullptr, nullptr);

src/wallet/bdb.h

@@ -223,6 +223,10 @@ public:
 
 std::string BerkeleyDatabaseVersion();
 
+/** Perform sanity check of runtime BDB version versus linked BDB version.
+ */
+bool BerkeleyDatabaseSanityCheck();
+
 //! Return object giving access to Berkeley database at specified path.
 std::unique_ptr<BerkeleyDatabase> MakeBerkeleyDatabase(const fs::path& path, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error);
 

src/wallet/init.cpp

@@ -86,6 +86,11 @@ void WalletInit::AddWalletOptions(ArgsManager& argsman) const
 
 bool WalletInit::ParameterInteraction() const
 {
+#ifdef USE_BDB
+     if (!BerkeleyDatabaseSanityCheck()) {
+         return InitError(Untranslated("A version conflict was detected between the run-time BerkeleyDB library and the one used during compilation."));
+     }
+#endif
     if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET)) {
         for (const std::string& wallet : gArgs.GetArgs("-wallet")) {
             LogPrintf("%s: parameter interaction: -disablewallet -> ignoring -wallet=%s\n", __func__, wallet);