just a little bit of refactoring

src/academy.c

@@ -19,6 +19,9 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <platform.h>
 #include <kernel/config.h>
 #include <kernel/unit.h>
+#include <kernel/building.h>
+#include <kernel/item.h>
+#include <kernel/pool.h>
 #include "academy.h"
 #include "study.h"
 
@@ -28,3 +31,15 @@ void academy_teaching_bonus(struct unit *u, skill_t sk, int academy) {
         learn_skill(u, sk, academy / 30.0 / TEACHNUMBER);
     }
 }
+
+bool academy_can_teach(unit *teacher, unit *student, skill_t sk) {
+    const struct building_type *btype = bt_find("academy");
+    if (active_building(teacher, btype) && active_building(student, btype)) {
+        int j = study_cost(student, sk);
+        j = _max(50, j * 2);
+        /* kann Einheit das zahlen? */
+        return get_pooled(student, get_resourcetype(R_SILVER), GET_DEFAULT, j) >= j;
+        /* sonst nehmen sie nicht am Unterricht teil */
+    }
+    return false;
+}

src/academy.h

@@ -9,7 +9,7 @@ extern "C" {
 
     struct unit;
     void academy_teaching_bonus(struct unit *u, skill_t sk, int academy);
-
+    bool academy_can_teach(struct unit *teacher, struct unit *student, skill_t sk);
 #ifdef __cplusplus
 }
 #endif

src/study.c

@@ -230,18 +230,13 @@ teach_unit(unit * teacher, unit * student, int nteaching, skill_t sk,
         if (student->building && teacher->building == student->building) {
             /* Solange Akademien groessenbeschraenkt sind, sollte Lehrer und
              * Student auch in unterschiedlichen Gebaeuden stehen duerfen */
-            const struct building_type *btype = bt_find("academy");
-            if (active_building(teacher, btype) && active_building(student, btype)) {
-                int j = study_cost(student, sk);
-                j = _max(50, j * 2);
-                /* kann Einheit das zahlen? */
-                if (get_pooled(student, get_resourcetype(R_SILVER), GET_DEFAULT, j) >= j) {
+            if (academy_can_teach(teacher, student, sk)) {
                 /* Jeder Schueler zusaetzlich +10 Tage wenn in Uni. */
                 teach->value += (n / 30) * 10;  /* learning erhoehen */
                                                 /* Lehrer zusaetzlich +1 Tag pro Schueler. */
-                    if (academy)
+                if (academy) {
                     *academy += n;
-                }                         /* sonst nehmen sie nicht am Unterricht teil */
+                }
             }
         }
         /* Teaching ist die Anzahl Leute, denen man noch was beibringen kann. Da

src/util/umlaut.c

@@ -171,7 +171,6 @@ void addtoken(void ** root, const char *str, variant id)
 
             ref = (tref *)malloc(sizeof(tref));
             ref->ucs = ucs;
-            ref->node = 0;
             ref->node = node;
             ref->nexthash = tk->next[index];
             tk->next[index] = ref;