snapshot restore don't remove terminating regions (#1968)

Author: PhilippTakacs

tests/unit/test_mem.c

@@ -280,6 +280,7 @@ static void test_snapshot(void)
     uc_engine *uc;
     uc_context *c0, *c1;
     uint32_t mem;
+    uint8_t code_data;
     // mov eax, [0x2020]; inc eax; mov [0x2020], eax
     char code[] = "\xa1\x20\x20\x00\x00\x00\x00\x00\x00\xff\xc0\xa3\x20\x20\x00"
                   "\x00\x00\x00\x00\x00";
@@ -302,13 +303,15 @@ static void test_snapshot(void)
     OK(uc_mem_read(uc, 0x2020, &mem, sizeof(mem)));
     TEST_CHECK(mem == 2);
     OK(uc_context_restore(uc, c1));
-    // TODO check mem
+
     OK(uc_mem_read(uc, 0x2020, &mem, sizeof(mem)));
     TEST_CHECK(mem == 1);
     OK(uc_context_restore(uc, c0));
     OK(uc_mem_read(uc, 0x2020, &mem, sizeof(mem)));
     TEST_CHECK(mem == 0);
-    // TODO check mem
+
+    OK(uc_mem_read(uc, 0x1000, &code_data, sizeof(code_data)));
+    TEST_CHECK(code_data == 0xa1);
 
     OK(uc_context_free(c0));
     OK(uc_context_free(c1));

uc.c

@@ -2837,7 +2837,7 @@ static uc_err uc_restore_latest_snapshot(struct uc_struct *uc)
                         subregions_link, subregion_next)
     {
         uc->memory_filter_subregions(subregion, uc->snapshot_level);
-        if (QTAILQ_EMPTY(&subregion->subregions)) {
+        if (subregion->priority >= uc->snapshot_level || (!subregion->terminates && QTAILQ_EMPTY(&subregion->subregions))) {
             uc->memory_unmap(uc, subregion);
         }
     }