create a test that crashes for bug 2194

src/study.c

@@ -205,7 +205,7 @@ teach_unit(unit * teacher, unit * student, int nteaching, skill_t sk,
 
     n = _min(n, nteaching);
 
-    if (n != 0) {
+    if (n != 0 && teacher->building && student->building) {
         const struct building_type *btype = bt_find("academy");
         int index = 0;
 

src/study.test.c

@@ -5,8 +5,11 @@
 #include <kernel/config.h>
 #include <kernel/unit.h>
 #include <kernel/faction.h>
+#include <kernel/item.h>
 #include <kernel/order.h>
 #include <kernel/region.h>
+#include <kernel/building.h>
+#include <util/rand.h>
 #include <util/message.h>
 #include <util/language.h>
 #include <util/base36.h>
@@ -21,6 +24,15 @@ typedef struct {
     unit *teachers[2];
 } study_fixture;
 
+static void setup_locale(struct locale *lang) {
+    int i;
+    for (i = 0; i < MAXSKILLS; ++i) {
+        if (!locale_getstring(lang, mkname("skill", skillnames[i])))
+            locale_setstring(lang, mkname("skill", skillnames[i]), skillnames[i]);
+    }
+    init_skills(lang);
+}
+
 static void setup_study(study_fixture *fix, skill_t sk) {
     struct region * r;
     struct faction *f;
@@ -33,8 +45,7 @@ static void setup_study(study_fixture *fix, skill_t sk) {
     r = findregion(0, 0);
     f = test_create_faction(0);
     lang = get_or_create_locale(locale_name(f->locale));
-    locale_setstring(lang, mkname("skill", skillnames[sk]), skillnames[sk]);
+    setup_locale(lang);
-    init_skills(lang);
     fix->u = test_create_unit(f, r);
     assert(fix->u);
     fix->u->thisorder = create_order(K_STUDY, f->locale, "%s", skillnames[sk]);
@@ -80,12 +91,10 @@ static void test_study_with_teacher(CuTest *tc) {
 static void test_study_with_bad_teacher(CuTest *tc) {
     study_fixture fix;
     skill *sv;
-    message *msg;
 
     setup_study(&fix, SK_CROSSBOW);
     teach_cmd(fix.teachers[0], fix.teachers[0]->thisorder);
-    CuAssertPtrNotNull(tc, msg = test_get_last_message(fix.u->faction->msgs));
+    CuAssertPtrNotNull(tc, test_find_messagetype(fix.u->faction->msgs, "teach_asgood"));
-    CuAssertStrEquals(tc, "teach_asgood", test_get_messagetype(msg));
     study_cmd(fix.u, fix.u->thisorder);
     CuAssertPtrNotNull(tc, sv = unit_skill(fix.u, SK_CROSSBOW));
     CuAssertIntEquals(tc, 1, sv->level);
@@ -93,11 +102,46 @@ static void test_study_with_bad_teacher(CuTest *tc) {
     test_cleanup();
 }
 
+static void test_study_bug_2194(CuTest *tc) {
+    unit *u, *u1, *u2;
+    struct locale * loc;
+    building * b;
+
+    test_cleanup();
+    random_source_inject_constant(0.0);
+    init_resources();
+    loc = get_or_create_locale("de");
+    setup_locale(loc);
+    u = test_create_unit(test_create_faction(0), test_create_region(0, 0, 0));
+    scale_number(u, 2);
+    set_level(u, SK_CROSSBOW, TEACHDIFFERENCE);
+    u->faction->locale = loc;
+    u1 = test_create_unit(u->faction, u->region);
+    scale_number(u1, 17);
+    u1->thisorder = create_order(K_STUDY, loc, skillnames[SK_CROSSBOW]);
+    u2 = test_create_unit(u->faction, u->region);
+    scale_number(u2, 3);
+    u2->thisorder = create_order(K_STUDY, loc, skillnames[SK_MAGIC]);
+    u->thisorder = create_order(K_TEACH, loc, "%s %s", itoa36(u1->no), itoa36(u2->no));
+    b = test_create_building(u->region, test_create_buildingtype("academy"));
+    b->size = 22;
+    u_set_building(u, b);
+    u_set_building(u1, b);
+    u_set_building(u2, b);
+    i_change(&u1->items, get_resourcetype(R_SILVER)->itype, 50);
+    i_change(&u2->items, get_resourcetype(R_SILVER)->itype, 50);
+    b->flags = BLD_WORKING;
+    teach_cmd(u, u->thisorder);
+    CuAssertPtrNotNull(tc, test_find_messagetype(u->faction->msgs, "teach_asgood"));
+    test_cleanup();
+}
+
 CuSuite *get_study_suite(void)
 {
     CuSuite *suite = CuSuiteNew();
     SUITE_ADD_TEST(suite, test_study_no_teacher);
     SUITE_ADD_TEST(suite, test_study_with_teacher);
     SUITE_ADD_TEST(suite, test_study_with_bad_teacher);
+    SUITE_ADD_TEST(suite, test_study_bug_2194);
     return suite;
 }