Fix plain thread ID is_main unsoundness when ana.thread.include-node …

…is disabled

src/cdomain/value/cdomains/threadIdDomain.ml

@@ -83,7 +83,7 @@ struct
       (v, None)
 
   let is_main = function
-    | ({vname; _}, None) -> List.mem vname @@ GobConfig.get_string_list "mainfun"
+    | ({vname; _}, None) -> GobConfig.get_bool "ana.thread.include-node" && List.mem vname @@ GobConfig.get_string_list "mainfun"
     | _ -> false
 
   let is_unique = is_main

tests/regression/51-threadjoins/11-join-main-plain-no-node.c

@@ -0,0 +1,29 @@
+//PARAM: --set ana.activated[+] threadJoins --set ana.thread.domain plain --disable ana.thread.include-node
+#include <pthread.h>
+#include <stdio.h>
+
+pthread_t mainid;
+
+int g = 10;
+
+void *t_fun(void *arg) {
+  int r = pthread_join(mainid, NULL); // TSan doesn't like this...
+  printf("j: %d\n", r);
+  g++; // RACE (imprecise by plain thread IDs)
+  printf("t_fun: %d\n", g);
+  return NULL;
+}
+
+
+int main(void) {
+  mainid = pthread_self();
+
+  pthread_t id2;
+  pthread_create(&id2, NULL, t_fun, NULL);
+
+  g++; // RACE (imprecise by plain thread IDs not knowing if main is actual main or spawned by program)
+  printf("main: %d\n", g);
+
+  pthread_exit(NULL); // exit main thread but keep id2 alive, otherwise main returning kills id2
+  return 0;
+}