commit cb6aa82dbc10d554f8d234e934ae7c77e39a3ce2
Author: Panu Matilainen <pmatilai@redhat.com>
Date:   Tue Jan 12 13:35:23 2021 +0200

    Unblock signals in forked scriptlets
    
    Since commit c5f82d3f6223ebd0c5cc0a07ea60393ae7284929 we've blocked
    most signals during transactions, which makes sense to rpm itself but
    the signal mask is inherited to childs and carried even across exec(),
    so all scriptlets are executing with those signals blocked as well.
    Which in turn does not make sense, the scriptlets could run stuff that
    actually depends on signal delivery (such as SIGALARM in RhBug:1913765).
    
    Unblock all signals for forked scriptlet execution (Lua scriptlets are
    totally different as they execute in-process for now)

diff --git a/lib/rpmscript.c b/lib/rpmscript.c
index 2ae3378f7..c69d29554 100644
--- a/lib/rpmscript.c
+++ b/lib/rpmscript.c
@@ -152,6 +152,11 @@ static void doScriptExec(ARGV_const_t argv, ARGV_const_t prefixes,
 			FD_t scriptFd, FD_t out)
 {
     int xx;
+    sigset_t set;
+
+    /* Unmask all signals, the scripts may need them */
+    sigfillset(&set);
+    sigprocmask(SIG_UNBLOCK, &set, NULL);
 
     /* SIGPIPE is ignored in rpm, reset to default for the scriptlet */
     (void) signal(SIGPIPE, SIG_DFL);