source/blender/draw/engines/eevee_next/shaders/eevee_shadow_page_defrag_comp.glsl

@@ -24,11 +24,14 @@ const uint max_page = SHADOW_MAX_PAGE;
 
 void find_first_valid(inout uint src, uint dst)
 {
-  for (; src < dst; src++) {
-    if (pages_cached_buf[src % max_page].x != uint(-1)) {
+  for (uint i = src; i < dst; i++) {
+    if (pages_cached_buf[i % max_page].x != uint(-1)) {
+      src = i;
       return;
     }
   }
+
+  src = dst;
 }
 
 void page_cached_free(uint page_index)

source/blender/draw/tests/eevee_test.cc

@@ -648,6 +648,10 @@ class TestAlloc {
     GPU_render_begin();
     int tiles_index = 1;
 
+    for (int i : IndexRange(SHADOW_MAX_TILE)) {
+      tiles_data[i] = 0;
+    }
+
     for (uint i : IndexRange(0, page_free_count)) {
       uint2 page = {i % SHADOW_PAGE_PER_ROW, i / SHADOW_PAGE_PER_ROW};
       pages_free_data[i] = page.x | (page.y << 16u);