From 34c80809f1c8206cd16e6bdd4beb58a4006bfd99 Mon Sep 17 00:00:00 2001
From: "A.Shakhmatov" <dev@shakhmatov.com>
Date: Sat, 21 Feb 2026 17:45:58 +0300
Subject: [PATCH] fix: prevent snapshot hang caused by u8 overflow in progress
 calculation

When creating/restoring snapshots with 4+ tables, the progress percentage
calculation overflowed u8 (e.g. 4*80=320 > 255), causing a panic that left
the IPC call unresolved. Also deduplicate fetch_foreign_keys_raw call.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src-tauri/src/commands/snapshot.rs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src-tauri/src/commands/snapshot.rs b/src-tauri/src/commands/snapshot.rs
index 8f93eaf..8ac093e 100644
--- a/src-tauri/src/commands/snapshot.rs
+++ b/src-tauri/src/commands/snapshot.rs
@@ -41,8 +41,10 @@ pub async fn create_snapshot(
         .map(|t| (t.schema.clone(), t.table.clone()))
         .collect();
 
+    // Fetch FK info once — used for both dependency expansion and topological sort
+    let fk_rows = fetch_foreign_keys_raw(&pool).await?;
+
     if params.include_dependencies {
-        let fk_rows = fetch_foreign_keys_raw(&pool).await?;
         for fk in &fk_rows {
             for (schema, table) in &params.tables.iter().map(|t| (t.schema.clone(), t.table.clone())).collect::<Vec<_>>() {
                 if &fk.schema == schema && &fk.table == table {
@@ -56,7 +58,6 @@ pub async fn create_snapshot(
     }
 
     // FK-based topological sort
-    let fk_rows = fetch_foreign_keys_raw(&pool).await?;
     let fk_edges: Vec<(String, String, String, String)> = fk_rows
         .iter()
         .map(|fk| (fk.schema.clone(), fk.table.clone(), fk.ref_schema.clone(), fk.ref_table.clone()))
@@ -75,7 +76,7 @@ pub async fn create_snapshot(
     let mut total_rows: u64 = 0;
 
     for (i, (schema, table)) in sorted_tables.iter().enumerate() {
-        let percent = 10 + ((i as u8) * 80 / total_tables.max(1) as u8);
+        let percent = (10 + (i * 80 / total_tables.max(1))).min(90) as u8;
         let _ = app.emit(
             "snapshot-progress",
             SnapshotProgress {
@@ -249,7 +250,7 @@ pub async fn restore_snapshot(
             continue;
         }
 
-        let percent = 20 + ((i as u8) * 75 / total_tables.max(1) as u8);
+        let percent = (20 + (i * 75 / total_tables.max(1))).min(95) as u8;
         let _ = app.emit(
             "snapshot-progress",
             SnapshotProgress {