Unify skip-review handling for approval_mode = "approve" (#20750)

## Summary
- Treat `approval_mode = "approve"` as skip-review across all permission
modes.
- Remove the mode-specific split in the MCP auto-approval gate so
approved tools bypass review consistently.
- Expand regression coverage in the shared MCP helper and the core
tool-call flow.

## Testing
- `just fmt`
- `cargo test -p codex-mcp`
- `cargo test -p codex-core
approve_mode_skips_arc_and_guardian_in_every_permission_mode`
- `git diff --check`
- Full `cargo test -p codex-core` was also attempted, but the suite hit
an unrelated pre-existing stack overflow in an existing multi-agent test

codex-rs/codex-mcp/src/mcp/mod.rs

@@ -71,12 +71,7 @@ pub fn mcp_permission_prompt_is_auto_approved(
     permission_profile: &PermissionProfile,
     context: McpPermissionPromptAutoApproveContext,
 ) -> bool {
-    if matches!(
-        approval_policy,
-        AskForApproval::OnRequest | AskForApproval::Granular(_)
-    ) && context.approvals_reviewer == Some(ApprovalsReviewer::AutoReview)
-        && context.tool_approval_mode == Some(AppToolApproval::Approve)
-    {
+    if context.tool_approval_mode == Some(AppToolApproval::Approve) {
         return true;
     }
 

codex-rs/codex-mcp/src/mcp/mod_tests.rs

@@ -74,16 +74,11 @@ fn mcp_prompt_auto_approval_honors_unrestricted_managed_profiles() {
 }
 
 #[test]
-fn mcp_prompt_auto_approval_honors_auto_review_approved_tools() {
-    assert!(mcp_permission_prompt_is_auto_approved(
+fn mcp_prompt_auto_approval_honors_approved_tools_in_all_permission_modes() {
+    for approval_policy in [
+        AskForApproval::UnlessTrusted,
+        AskForApproval::OnFailure,
         AskForApproval::OnRequest,
-        &PermissionProfile::read_only(),
-        McpPermissionPromptAutoApproveContext {
-            approvals_reviewer: Some(ApprovalsReviewer::AutoReview),
-            tool_approval_mode: Some(AppToolApproval::Approve),
-        },
-    ));
-    assert!(mcp_permission_prompt_is_auto_approved(
         AskForApproval::Granular(GranularApprovalConfig {
             sandbox_approval: true,
             rules: true,
@@ -91,34 +86,36 @@ fn mcp_prompt_auto_approval_honors_auto_review_approved_tools() {
             request_permissions: true,
             mcp_elicitations: true,
         }),
+        AskForApproval::Never,
+    ] {
+        assert!(mcp_permission_prompt_is_auto_approved(
+            approval_policy,
+            &PermissionProfile::read_only(),
+            McpPermissionPromptAutoApproveContext {
+                approvals_reviewer: Some(ApprovalsReviewer::User),
+                tool_approval_mode: Some(AppToolApproval::Approve),
+            },
+        ));
+    }
+
+    assert!(!mcp_permission_prompt_is_auto_approved(
+        AskForApproval::OnRequest,
         &PermissionProfile::read_only(),
         McpPermissionPromptAutoApproveContext {
             approvals_reviewer: Some(ApprovalsReviewer::AutoReview),
-            tool_approval_mode: Some(AppToolApproval::Approve),
+            tool_approval_mode: Some(AppToolApproval::Auto),
         },
     ));
+}
+
+#[test]
+fn mcp_prompt_auto_approval_rejects_auto_mode_in_default_permission_mode() {
     assert!(!mcp_permission_prompt_is_auto_approved(
         AskForApproval::OnRequest,
         &PermissionProfile::read_only(),
         McpPermissionPromptAutoApproveContext {
             approvals_reviewer: Some(ApprovalsReviewer::User),
-            tool_approval_mode: Some(AppToolApproval::Approve),
-        },
-    ));
-    assert!(!mcp_permission_prompt_is_auto_approved(
-        AskForApproval::OnFailure,
-        &PermissionProfile::read_only(),
-        McpPermissionPromptAutoApproveContext {
-            approvals_reviewer: Some(ApprovalsReviewer::AutoReview),
-            tool_approval_mode: Some(AppToolApproval::Approve),
-        },
-    ));
-    assert!(!mcp_permission_prompt_is_auto_approved(
-        AskForApproval::UnlessTrusted,
-        &PermissionProfile::read_only(),
-        McpPermissionPromptAutoApproveContext {
-            approvals_reviewer: Some(ApprovalsReviewer::AutoReview),
-            tool_approval_mode: Some(AppToolApproval::Approve),
+            tool_approval_mode: Some(AppToolApproval::Auto),
         },
     ));
 }