[C]: for #424. Reflect Java changes for unblock.

aeron-driver/src/main/c/concurrent/aeron_logbuffer_unblocker.c

@@ -28,22 +28,28 @@ bool aeron_logbuffer_unblocker_unblock(
     AERON_GET_VOLATILE(active_term_count, log_meta_data->active_term_count);
     const int32_t expected_term_count = (int32_t)(blocked_position >> position_bits_to_shift);
 
-    const size_t index = aeron_logbuffer_index_by_term_count(active_term_count);
+    const size_t index = aeron_logbuffer_index_by_term_count(expected_term_count);
 
     int64_t raw_tail;
 
     AERON_GET_VOLATILE(raw_tail, log_meta_data->term_tail_counters[index]);
     const int32_t term_id = aeron_logbuffer_term_id(raw_tail);
-
-    if (active_term_count == (expected_term_count - 1) && 0 == (blocked_position & (term_length - 1)))
-    {
-        return aeron_logbuffer_rotate_log(log_meta_data, active_term_count, term_id);
-    }
-
     const int32_t tail_offset = aeron_logbuffer_term_offset(raw_tail, (int32_t)term_length);
     const int32_t blocked_offset =
         aeron_logbuffer_compute_term_offset_from_position(blocked_position, position_bits_to_shift);
 
+    if (active_term_count == (expected_term_count - 1) && 0 == blocked_offset)
+    {
+        int64_t current_raw_tail;
+
+        AERON_GET_VOLATILE(
+            current_raw_tail,
+            log_meta_data->term_tail_counters[aeron_logbuffer_index_by_term_count(active_term_count)]);
+        const int32_t current_term_id = aeron_logbuffer_term_id(current_raw_tail);
+
+        return aeron_logbuffer_rotate_log(log_meta_data, active_term_count, current_term_id);
+    }
+
     switch (aeron_term_unblocker_unblock(
         log_meta_data, term_buffers[index].addr, term_length, blocked_offset, tail_offset, term_id))
     {