Rewrite control_event_signal() to use signal_table.

When we added the ACTIVE and DORMANT virtual signals, we taught the
signal command to handle them, but we didn't teach SIGNAL event to
report them.

To solve this problem and prevent it from recurring, this patch
revises the implementation of control_event_signal() to use the same
signal_table that handle_control_signal() uses.  This way, the two
controller commands can't become out of sync.

Fixes bug 33104; bugfix on 0.4.0.1-alpha.

2 files changed, 14 insertions, 22 deletions

diff --git a/src/feature/control/control.c b/src/feature/control/control.c
index 436bf423cf..71b864751f 100644
--- a/src/feature/control/control.c
+++ b/src/feature/control/control.c
@@ -158,6 +158,10 @@ control_ports_write_to_file(void)
 }
 
 const struct signal_name_t signal_table[] = {
+  /* NOTE: this table is used for handling SIGNAL commands and generating
+   * SIGNAL events.  Order is significant: if there are two entries for the
+   * same numeric signal, the first one is the canonical name generated
+   * for the events. */
   { SIGHUP, "RELOAD" },
   { SIGHUP, "HUP" },
   { SIGINT, "SHUTDOWN" },
diff --git a/src/feature/control/control_events.c b/src/feature/control/control_events.c
index 9e0966ca54..1089b608b7 100644
--- a/src/feature/control/control_events.c
+++ b/src/feature/control/control_events.c
@@ -1552,29 +1552,17 @@ control_event_signal(uintptr_t signal_num)
   if (!control_event_is_interesting(EVENT_GOT_SIGNAL))
     return 0;
 
-  switch (signal_num) {
-    case SIGHUP:
-      signal_string = "RELOAD";
+  for (unsigned i = 0; signal_table[i].signal_name != NULL; ++i) {
+    if ((int)signal_num == signal_table[i].sig) {
+      signal_string = signal_table[i].signal_name;
       break;
-    case SIGUSR1:
-      signal_string = "DUMP";
-      break;
-    case SIGUSR2:
-      signal_string = "DEBUG";
-      break;
-    case SIGNEWNYM:
-      signal_string = "NEWNYM";
-      break;
-    case SIGCLEARDNSCACHE:
-      signal_string = "CLEARDNSCACHE";
-      break;
-    case SIGHEARTBEAT:
-      signal_string = "HEARTBEAT";
-      break;
-    default:
-      log_warn(LD_BUG, "Unrecognized signal %lu in control_event_signal",
-               (unsigned long)signal_num);
-      return -1;
+    }
+  }
+
+  if (signal_string == NULL) {
+    log_warn(LD_BUG, "Unrecognized signal %lu in control_event_signal",
+             (unsigned long)signal_num);
+    return -1;
   }
 
   send_control_event(EVENT_GOT_SIGNAL,  "650 SIGNAL %s\r\n",