fix(dream): filter non-Dream history commits (#4905)

* fix(dream): filter non-Dream history commits

* fix(dream): resolve filtered commit diffs

nanobot/command/builtin.py

@@ -560,6 +560,9 @@ def _format_changed_files(diff: str) -> str:
     return ", ".join(f"`{path}`" for path in files)
 
 
+_DREAM_COMMIT_PREFIX = "dream:"
+
+
 def _format_dream_log_content(commit, diff: str, *, requested_sha: str | None = None) -> str:
     files_line = _format_changed_files(diff)
     lines = [
@@ -608,7 +611,7 @@ def _format_dream_restore_list(commits: list) -> str:
 async def cmd_dream_log(ctx: CommandContext) -> OutboundMessage:
     """Show what the last Dream changed.
 
-    Default: diff of the latest commit (HEAD~1 vs HEAD).
+    Default: diff of the latest Dream commit versus its parent.
     With /dream-log <sha>: diff of that specific commit.
     """
     store = ctx.loop.consolidator.store
@@ -643,9 +646,16 @@ async def cmd_dream_log(ctx: CommandContext) -> OutboundMessage:
             commit, diff = result
             content = _format_dream_log_content(commit, diff, requested_sha=sha)
     else:
-        # Default: show the latest commit's diff
-        commits = git.log(max_entries=1)
-        result = git.show_commit_diff(commits[0].sha) if commits else None
+        # Default: show the latest Dream commit's diff
+        commits = git.log(max_entries=1, message_prefix=_DREAM_COMMIT_PREFIX)
+        result = (
+            git.show_commit_diff(
+                commits[0].sha,
+                max_entries=1,
+                message_prefix=_DREAM_COMMIT_PREFIX,
+            )
+            if commits else None
+        )
         if result:
             commit, diff = result
             content = _format_dream_log_content(commit, diff)
@@ -678,17 +688,24 @@ async def cmd_dream_restore(ctx: CommandContext) -> OutboundMessage:
 
     args = ctx.args.strip()
     if not args:
-        # Show recent commits for the user to pick
-        commits = git.log(max_entries=10)
+        # Show recent Dream commits for the user to pick
+        commits = git.log(max_entries=10, message_prefix=_DREAM_COMMIT_PREFIX)
         if not commits:
             content = "Dream memory has no saved versions to restore yet."
         else:
             content = _format_dream_restore_list(commits)
     else:
         sha = args.split()[0]
-        result = git.show_commit_diff(sha)
-        changed_files = _format_changed_files(result[1]) if result else "the tracked memory files"
-        new_sha = git.revert(sha)
+        result = git.show_commit_diff(sha, message_prefix=_DREAM_COMMIT_PREFIX)
+        if not result:
+            content = (
+                f"Couldn't restore Dream change `{sha}`.\n\n"
+                "Only Dream memory versions can be restored. "
+                "Use `/dream-restore` to list recent versions."
+            )
+        else:
+            changed_files = _format_changed_files(result[1])
+            new_sha = git.revert(sha, message_prefix=_DREAM_COMMIT_PREFIX)
             if new_sha:
                 content = (
                     f"Restored Dream memory to the state before `{sha}`.\n\n"
@@ -699,7 +716,7 @@ async def cmd_dream_restore(ctx: CommandContext) -> OutboundMessage:
             else:
                 content = (
                     f"Couldn't restore Dream change `{sha}`.\n\n"
-                "It may not exist, or it may be the first saved version with no earlier state to restore."
+                    "It may be the first saved version with no earlier state to restore."
                 )
     return OutboundMessage(
         channel=ctx.msg.channel, chat_id=ctx.msg.chat_id,

nanobot/utils/gitstore.py

@@ -214,8 +214,16 @@ class GitStore:
 
     # -- query -----------------------------------------------------------------
 
-    def log(self, max_entries: int = 20) -> list[CommitInfo]:
-        """Return simplified commit log."""
+    def log(
+        self,
+        max_entries: int = 20,
+        message_prefix: str | None = None,
+    ) -> list[CommitInfo]:
+        """Return simplified commit log, optionally filtered by message prefix.
+
+        When filtering, *max_entries* counts matching commits rather than every
+        commit traversed in the repository.
+        """
         if not self.is_initialized():
             return []
 
@@ -239,6 +247,7 @@ class GitStore:
                         time.localtime(commit.commit_time),
                     )
                     msg = commit.message.decode("utf-8", errors="replace").strip()
+                    if message_prefix is None or msg.startswith(message_prefix):
                         entries.append(CommitInfo(
                             sha=sha.hex()[:8],
                             message=msg,
@@ -424,25 +433,41 @@ class GitStore:
                 return c
         return None
 
-    def show_commit_diff(self, short_sha: str, max_entries: int = 20) -> tuple[CommitInfo, str] | None:
-        """Find a commit and return it with its diff vs the parent."""
-        commits = self.log(max_entries=max_entries)
-        for i, c in enumerate(commits):
+    def show_commit_diff(
+        self,
+        short_sha: str,
+        max_entries: int = 20,
+        message_prefix: str | None = None,
+    ) -> tuple[CommitInfo, str] | None:
+        """Find a commit and return it with its diff vs its actual parent."""
+        try:
+            from dulwich.repo import Repo
+
+            commits = self.log(max_entries=max_entries, message_prefix=message_prefix)
+            for c in commits:
                 if c.sha.startswith(short_sha):
-                if i + 1 < len(commits):
-                    diff = self.diff_commits(commits[i + 1].sha, c.sha)
-                else:
-                    diff = ""
+                    full_sha = self._resolve_sha(c.sha)
+                    if not full_sha:
+                        return None
+                    with Repo(str(self._workspace)) as repo:
+                        commit = repo[full_sha]
+                        parent = commit.parents[0] if commit.parents else None
+                    diff = self.diff_commits(parent.hex()[:8], c.sha) if parent else ""
                     return c, diff
             return None
+        except Exception:
+            logger.exception("Git show_commit_diff failed")
+            return None
 
     # -- restore ---------------------------------------------------------------
 
-    def revert(self, commit: str) -> str | None:
+    def revert(self, commit: str, *, message_prefix: str | None = None) -> str | None:
         """Revert (undo) the changes introduced by the given commit.
 
         Restores all tracked memory files to the state at the commit's parent,
-        then creates a new commit recording the revert.
+        then creates a new commit recording the revert. When *message_prefix*
+        is provided, commits outside that history are rejected before any files
+        are changed.
 
         Returns the new commit SHA, or None on failure.
         """
@@ -462,6 +487,15 @@ class GitStore:
                 if commit_obj.type_name != b"commit":
                     return None
 
+                commit_message = commit_obj.message.decode("utf-8", errors="replace").strip()
+                if message_prefix is not None and not commit_message.startswith(message_prefix):
+                    logger.warning(
+                        "Git revert: commit {} does not match message prefix {!r}",
+                        commit,
+                        message_prefix,
+                    )
+                    return None
+
                 if not commit_obj.parents:
                     logger.warning("Git revert: cannot revert root commit {}", commit)
                     return None

tests/agent/test_git_store.py

@@ -117,6 +117,17 @@ class TestLog:
             git_ready.auto_commit(f"c{i}")
         assert len(git_ready.log(max_entries=3)) == 3
 
+    def test_message_prefix_skips_unrelated_commits_before_counting_limit(self, git_ready):
+        ws = git_ready._workspace
+        messages = ["dream: older", "backup: first", "dream: latest", "backup: newest"]
+        for i, message in enumerate(messages):
+            (ws / "SOUL.md").write_text(f"v{i}", encoding="utf-8")
+            git_ready.auto_commit(message)
+
+        commits = git_ready.log(max_entries=2, message_prefix="dream:")
+
+        assert [commit.message for commit in commits] == ["dream: latest", "dream: older"]
+
     def test_commit_info_fields(self, git_ready):
         c = git_ready.log()[0]
         assert isinstance(c, CommitInfo)
@@ -178,6 +189,25 @@ class TestShowCommitDiff:
     def test_returns_none_for_unknown(self, git_ready):
         assert git_ready.show_commit_diff("deadbeef") is None
 
+    def test_message_prefix_finds_commit_beyond_unrelated_history_window(self, git_ready):
+        ws = git_ready._workspace
+        (ws / "SOUL.md").write_text("dream content", encoding="utf-8")
+        dream_sha = git_ready.auto_commit("dream: latest")
+        for i in range(20):
+            (ws / "SOUL.md").write_text(f"backup {i}", encoding="utf-8")
+            git_ready.auto_commit(f"backup: {i}")
+
+        result = git_ready.show_commit_diff(
+            dream_sha,
+            max_entries=1,
+            message_prefix="dream:",
+        )
+
+        assert result is not None
+        commit, diff = result
+        assert commit.sha == dream_sha
+        assert "dream content" in diff
+
 
 class TestCommitInfoFormat:
     def test_format_with_diff(self):
@@ -221,6 +251,19 @@ class TestRevert:
     def test_invalid_sha_returns_none(self, git_ready):
         assert git_ready.revert("deadbeef") is None
 
+    def test_message_prefix_rejects_unrelated_commit_without_changing_files(self, git_ready):
+        ws = git_ready._workspace
+        (ws / "SOUL.md").write_text("dream v1", encoding="utf-8")
+        git_ready.auto_commit("dream: v1")
+        (ws / "SOUL.md").write_text("backup state", encoding="utf-8")
+        backup_sha = git_ready.auto_commit("backup: workspace")
+        (ws / "SOUL.md").write_text("dream v2", encoding="utf-8")
+        latest_sha = git_ready.auto_commit("dream: v2")
+
+        assert git_ready.revert(backup_sha, message_prefix="dream:") is None
+        assert (ws / "SOUL.md").read_text(encoding="utf-8") == "dream v2"
+        assert git_ready.log()[0].sha == latest_sha
+
 
 class TestMemoryStoreGitProperty:
     def test_git_property_exposes_gitstore(self, tmp_path):

tests/command/test_builtin_dream.py

@@ -65,17 +65,34 @@ class _FakeGit:
         self._commits = commits or []
         self._diff_map = diff_map or {}
         self._revert_result = revert_result
+        self.revert_calls: list[tuple[str, str | None]] = []
 
     def is_initialized(self) -> bool:
         return self._initialized
 
-    def log(self, max_entries: int = 20) -> list[CommitInfo]:
-        return self._commits[:max_entries]
+    def log(
+        self,
+        max_entries: int = 20,
+        message_prefix: str | None = None,
+    ) -> list[CommitInfo]:
+        commits = self._commits
+        if message_prefix is not None:
+            commits = [c for c in commits if c.message.startswith(message_prefix)]
+        return commits[:max_entries]
 
-    def show_commit_diff(self, sha: str, max_entries: int = 20):
-        return self._diff_map.get(sha)
+    def show_commit_diff(
+        self,
+        sha: str,
+        max_entries: int = 20,
+        message_prefix: str | None = None,
+    ):
+        result = self._diff_map.get(sha)
+        if result and message_prefix is not None and not result[0].message.startswith(message_prefix):
+            return None
+        return result
 
-    def revert(self, sha: str) -> str | None:
+    def revert(self, sha: str, *, message_prefix: str | None = None) -> str | None:
+        self.revert_calls.append((sha, message_prefix))
         return self._revert_result
 
     def auto_commit(self, message: str) -> str | None:
@@ -260,6 +277,26 @@ async def test_dream_log_latest_is_more_user_friendly() -> None:
     assert "```diff" in out.content
 
 
+@pytest.mark.asyncio
+async def test_dream_log_latest_skips_non_dream_commit() -> None:
+    backup = CommitInfo(
+        sha="bbbb2222", message="backup: workspace snapshot", timestamp="2026-04-04 13:00",
+    )
+    dream = CommitInfo(
+        sha="abcd1234", message="dream: latest", timestamp="2026-04-04 12:00",
+    )
+    diff = "diff --git a/SOUL.md b/SOUL.md\n"
+    git = _FakeGit(
+        commits=[backup, dream],
+        diff_map={dream.sha: (dream, diff), backup.sha: (backup, "unrelated diff")},
+    )
+
+    out = await cmd_dream_log(_make_ctx("/dream-log", git))
+
+    assert "`abcd1234`" in out.content
+    assert "`bbbb2222`" not in out.content
+
+
 @pytest.mark.asyncio
 async def test_dream_log_missing_commit_guides_user() -> None:
     git = _FakeGit(diff_map={})
@@ -357,6 +394,7 @@ def test_dream_prompt_command_in_help_and_palette() -> None:
 async def test_dream_restore_lists_versions_with_next_steps() -> None:
     commits = [
         CommitInfo(sha="abcd1234", message="dream: latest", timestamp="2026-04-04 12:00"),
+        CommitInfo(sha="cccc3333", message="backup: workspace", timestamp="2026-04-04 10:00"),
         CommitInfo(sha="bbbb2222", message="dream: older", timestamp="2026-04-04 08:00"),
     ]
     git = _FakeGit(commits=commits)
@@ -366,6 +404,8 @@ async def test_dream_restore_lists_versions_with_next_steps() -> None:
     assert "## Dream Restore" in out.content
     assert "Choose a Dream memory version to restore." in out.content
     assert "`abcd1234` 2026-04-04 12:00 - dream: latest" in out.content
+    assert "`bbbb2222` 2026-04-04 08:00 - dream: older" in out.content
+    assert "backup: workspace" not in out.content
     assert "Preview a version with `/dream-log <sha>`" in out.content
     assert "Restore a version with `/dream-restore <sha>`." in out.content
 
@@ -398,3 +438,21 @@ async def test_dream_restore_success_mentions_files_and_followup() -> None:
     assert "- New safety commit: `eeee9999`" in out.content
     assert "- Restored files: `SOUL.md`, `memory/MEMORY.md`" in out.content
     assert "Use `/dream-log eeee9999` to inspect the restore diff." in out.content
+    assert git.revert_calls == [("abcd1234", "dream:")]
+
+
+@pytest.mark.asyncio
+async def test_dream_restore_rejects_non_dream_commit_clearly() -> None:
+    commit = CommitInfo(
+        sha="cccc3333", message="backup: workspace", timestamp="2026-04-04 10:00",
+    )
+    git = _FakeGit(
+        diff_map={commit.sha: (commit, "unrelated diff")},
+        revert_result="eeee9999",
+    )
+
+    out = await cmd_dream_restore(_make_ctx("/dream-restore cccc3333", git, args="cccc3333"))
+
+    assert "Only Dream memory versions can be restored." in out.content
+    assert "Use `/dream-restore` to list recent versions." in out.content
+    assert git.revert_calls == []