Runtime plugin/UDF load errors are silently lost when server runs with --silent-startup

A server started with --silent-startup silently swallows plugin/UDF load errors at runtime. Operations such as INSTALL PLUGIN and CREATE FUNCTION ... SONAME that fail to open a library return success instead of raising ER_CANT_OPEN_LIBRARY (1126): no error reaches the client and the statement wrongly succeeds.

Reproduce

Run the main.ps test with the server started with --silent-startup:

cd mysql-test

./mtr main.ps --mysqld=--silent-startup

More generally, with any server run with --silent-startup, run a statement that loads a non-existent library, e.g. CREATE FUNCTION myfunc RETURNS INTEGER SONAME 'no_such.so'.

Result

Expected: fails with ER_CANT_OPEN_LIBRARY (1126).

Actual: succeeds, no error raised. In main.ps:

mysqltest: At line 2605: query 'call proc_1()' succeeded - should have failed with error ER_CANT_OPEN_LIBRARY (1126)

Without --silent-startup (the stock MTR baseline) the test passes, which is why this is not caught in normal CI.

Root cause

Regression from commit 7828fb475b0 (MDEV-32745), which guarded the plugin-load my_error() calls in sql/sql_plugin.cc with opt_silent_startup:

if (!(plugin_dl.handle= dlopen(dlpath, RTLD_NOW)))

{

  if (!opt_silent_startup)

    my_error(ER_CANT_OPEN_LIBRARY, MyFlags, dlpath, errno, my_dlerror(dlpath));

  goto ret;

}

opt_silent_startup is a lifetime global — set once from the command line and never reset after startup completes. So the guard suppresses the error for the whole server lifetime, not just during startup. Skipping my_error() means the diagnostics area is never set, so the runtime statement reports no error. The option is meant to silence only the startup error log (help text: "Don't print [Note] or failed plugin_loads during startup"), never runtime SQL errors.

Fix

Startup callers pass MYF(ME_ERROR_LOG) (errors go to the error log); runtime callers (e.g. mysql_install_plugin) pass MYF(0) (errors go to the client). The fix keys the silencing off that flag instead of the lifetime global:

/* Silence plugin-load errors only on the startup error-log path, never at runtime. */

static inline bool silent_plugin_startup(myf MyFlags)

{

  return opt_silent_startup && (MyFlags & ME_ERROR_LOG);

}

All plugin-load my_error() guards in sql/sql_plugin.cc use !silent_plugin_startup(MyFlags) instead of !opt_silent_startup.

Affects

• Introduced by: 7828fb475b0 (MDEV-32745)
• Any server run with --silent-startup: runtime INSTALL PLUGIN / CREATE FUNCTION ... SONAME failures are silently ignored.
• Still present in mariadb/main; not addressed by the followup 04e09010773.