fix: use correct rollback tails for empty frames without history

src/tests/simple_tests/storage.rs

@@ -2,41 +2,35 @@
 mod tests {
     use crate::tests::simple_tests::{asm_tests::run_asm_based_test, Options};
 
-    #[test_log::test]
-    fn test_pubdata_and_storage_writes() {
+    fn test_snapshot_every_cycle(dir: &str, additional_contracts: &[i32]) {
         run_asm_based_test(
-            "src/tests/simple_tests/testdata/log/storage/storage_writes",
-            &[],
+            &format!("src/tests/simple_tests/testdata/{}", dir),
+            additional_contracts,
             Options {
+                // Do only 1 cycle per VM snapshot to really test all the boundary conditions.
                 cycles_per_vm_snapshot: 1,
                 ..Default::default()
             },
-        );
+        )
+    }
+
+    #[test_log::test]
+    fn test_pubdata_and_storage_writes() {
+        test_snapshot_every_cycle("log/storage/storage_writes", &[]);
     }
 
     #[test_log::test]
     fn test_storage_reads() {
-        run_asm_based_test(
-            "src/tests/simple_tests/testdata/log/storage/storage_reads",
-            &[],
-            Options {
-                // Do only 1 cycle per VM snapshot to really test all the boundary conditions.
-                cycles_per_vm_snapshot: 1,
-                ..Default::default()
-            },
-        )
+        test_snapshot_every_cycle("log/storage/storage_reads", &[]);
+    }
+
+    #[test_log::test]
+    fn test_storage_write_after_panic() {
+        test_snapshot_every_cycle("log/storage/storage_write_after_panic", &[]);
     }
 
     #[test_log::test]
     fn test_storage_pubdata_refunds() {
-        run_asm_based_test(
-            "src/tests/simple_tests/testdata/log/storage/storage_pubdata_refunds",
-            &[],
-            Options {
-                // Do only 1 cycle per VM snapshot to really test all the boundary conditions.
-                cycles_per_vm_snapshot: 1,
-                ..Default::default()
-            },
-        );
+        test_snapshot_every_cycle("log/storage/storage_pubdata_refunds", &[]);
     }
 }

src/tests/simple_tests/testdata/log/storage/storage_write_after_panic/entry.asm

@@ -0,0 +1,19 @@
+        .text
+        .file	"Test_26"
+        .rodata.cst32
+        .p2align	5
+        .text
+        .globl	__entry
+__entry:
+.main:  
+        add 1000, r0, r3
+        near_call r3, @test_invalid, @expected_panic
+        revert("Near call not panicked")
+
+test_invalid:
+        ret.panic r0
+
+expected_panic:
+        ; check that we can access storage after panic
+        log.swrite r0, r0, r0
+        ret.ok r0

src/witness/oracle.rs

@@ -552,8 +552,35 @@ pub fn create_artifacts_from_tracer<
         // wherever we have this marker we should look at the tail of the item right before it
         let pos = log_position_mapping[&rollback_tail_marker];
         let tail = if pos == -1 {
-            // empty
-            global_end_of_storage_log
+            if frame_index > 1 {
+                // empty frame
+                let pos_forward_head =
+                    log_position_mapping[&ExtendedLogQuery::FrameForwardHeadMarker(frame_index)];
+                let pos_forward_tail =
+                    log_position_mapping[&ExtendedLogQuery::FrameForwardTailMarker(frame_index)];
+                let pos_rollback_head =
+                    log_position_mapping[&ExtendedLogQuery::FrameRollbackHeadMarker(frame_index)];
+
+                if pos_forward_head == -1 && pos_forward_tail == -1 && pos_rollback_head == -1 {
+                    // absolutely empty frame, most likely leaf one,
+                    // but we can not just use global end,
+                    // instead we should use previous frame's data
+                    let pos_previous_frame_forward_tail = log_position_mapping
+                        [&ExtendedLogQuery::FrameForwardTailMarker(frame_index - 1)];
+                    if pos_previous_frame_forward_tail != -1 {
+                        let pointer = pos_previous_frame_forward_tail as usize;
+                        let element = chain_of_states[pointer].2 .0;
+
+                        element
+                    } else {
+                        global_end_of_storage_log
+                    }
+                } else {
+                    global_end_of_storage_log
+                }
+            } else {
+                global_end_of_storage_log
+            }
         } else {
             let pointer = pos as usize;
             let element = chain_of_states[pointer].2 .1;