Pad mip-map buffers to allow for uint64_t write word

[pulseview.git] / pv / data / logicsnapshot.cpp

diff --git a/pv/data/logicsnapshot.cpp b/pv/data/logicsnapshot.cpp
index 5665d35f8c3d58916b3df6ed41c11227f13d39cf..af6ac0e8c367a097372aeea376cef6c101785e8b 100644 (file)
--- a/pv/data/logicsnapshot.cpp
+++ b/pv/data/logicsnapshot.cpp
@@ -77,7 +77,10 @@ void LogicSnapshot::reallocate_mip_map(MipMapLevel &m)
        if (new_data_length > m.data_length)
        {
                m.data_length = new_data_length;
-               m.data = realloc(m.data, new_data_length * _unit_size);
+
+               // Padding is added to allow for the uint64_t write word
+               m.data = realloc(m.data, new_data_length * _unit_size +
+                       sizeof(uint64_t));
        }
 }
 
@@ -204,7 +207,10 @@ void LogicSnapshot::get_subsampled_edges(
        {
                //----- Continue to search -----//
                level = min_level;
-               fast_forward = true;
+
+               // We cannot fast-forward if there is no mip-map data at
+               // at the minimum level.
+               fast_forward = (_mip_map[level].data != NULL);
 
                if (min_length < MipMapScaleFactor)
                {
@@ -241,7 +247,8 @@ void LogicSnapshot::get_subsampled_edges(
                        // We can fast forward only if there was no change
                        const bool sample =
                                (get_sample(index) & sig_mask) != 0;
-                       fast_forward = last_sample == sample;
+                       if (last_sample != sample)
+                               fast_forward = false;
                }
 
                if (fast_forward) {