Merge 'fix opcodes missing a database register' from Glauber Costa

Two of the opcodes we implement (OpenRead and Transaction) should have
an opcode specifying the database to use, but they don't.
Add it, and for now always use 0 (the main database).

Reviewed-by: Pere Diaz Bou <pere-altea@homail.com>

Closes #2191

core/translate/index.rs

@@ -130,6 +130,7 @@ pub fn translate_create_index(
     program.emit_insn(Insn::OpenRead {
         cursor_id: table_cursor_id,
         root_page: tbl.root_page,
+        db: 0,
     });
 
     let loop_start_label = program.allocate_label();

core/translate/main_loop.rs

@@ -207,12 +207,14 @@ pub fn init_loop(
                         program.emit_insn(Insn::OpenRead {
                             cursor_id,
                             root_page,
+                            db: 0,
                         });
                     }
                     if let Some(index_cursor_id) = index_cursor_id {
                         program.emit_insn(Insn::OpenRead {
                             cursor_id: index_cursor_id,
                             root_page: index.as_ref().unwrap().root_page,
+                            db: 0,
                         });
                     }
                 }
@@ -283,6 +285,7 @@ pub fn init_loop(
                             program.emit_insn(Insn::OpenRead {
                                 cursor_id: table_cursor_id,
                                 root_page: table.table.get_root_page(),
+                                db: 0,
                             });
                         }
                     }
@@ -341,6 +344,7 @@ pub fn init_loop(
                                     cursor_id: index_cursor_id
                                         .expect("index cursor is always opened in Seek with index"),
                                     root_page: index.root_page,
+                                    db: 0,
                                 });
                             }
                             OperationMode::UPDATE | OperationMode::DELETE => {

core/translate/schema.rs

@@ -806,6 +806,7 @@ pub fn translate_drop_table(
         program.emit_insn(Insn::OpenRead {
             cursor_id: sqlite_schema_cursor_id_1,
             root_page: 1usize,
+            db: 0,
         });
 
         let schema_column_0_register = program.alloc_register();

core/translate/transaction.rs

@@ -22,7 +22,7 @@ pub fn translate_tx_begin(
             });
         }
         TransactionType::Immediate | TransactionType::Exclusive => {
-            program.emit_insn(Insn::Transaction { write: true });
+            program.emit_insn(Insn::Transaction { db: 0, write: true });
             // TODO: Emit transaction instruction on temporary tables when we support them.
             program.emit_insn(Insn::AutoCommit {
                 auto_commit: false,

core/vdbe/builder.rs

@@ -768,8 +768,11 @@ impl ProgramBuilder {
             self.preassign_label_to_next_insn(self.init_label);
 
             match txn_mode {
-                TransactionMode::Read => self.emit_insn(Insn::Transaction { write: false }),
-                TransactionMode::Write => self.emit_insn(Insn::Transaction { write: true }),
+                TransactionMode::Read => self.emit_insn(Insn::Transaction {
+                    db: 0,
+                    write: false,
+                }),
+                TransactionMode::Write => self.emit_insn(Insn::Transaction { db: 0, write: true }),
                 TransactionMode::None => {}
             }
 

core/vdbe/execute.rs

@@ -876,6 +876,7 @@ pub fn op_open_read(
     let Insn::OpenRead {
         cursor_id,
         root_page,
+        db,
     } = insn
     else {
         unreachable!("unexpected Insn {:?}", insn)
@@ -1912,7 +1913,7 @@ pub fn op_transaction(
     pager: &Rc<Pager>,
     mv_store: Option<&Rc<MvStore>>,
 ) -> Result<InsnFunctionStepResult> {
-    let Insn::Transaction { write } = insn else {
+    let Insn::Transaction { db: 0, write } = insn else {
         unreachable!("unexpected Insn {:?}", insn)
     };
     let conn = program.connection.clone();

core/vdbe/explain.rs

@@ -357,11 +357,12 @@ pub fn insn_to_str(
             Insn::OpenRead {
                 cursor_id,
                 root_page,
+                db,
             } => (
                 "OpenRead",
                 *cursor_id as i32,
                 *root_page as i32,
-                0,
+                *db as i32,
                 Value::build_text(""),
                 0,
                 {
@@ -377,10 +378,11 @@ pub fn insn_to_str(
                                 }
                             });
                     format!(
-                        "{}={}, root={}",
+                        "{}={}, root={}, iDb={}",
                         cursor_type,
                         get_table_or_index_name(*cursor_id),
-                        root_page
+                        root_page,
+                        db
                     )
                 },
             ),
@@ -645,14 +647,14 @@ pub fn insn_to_str(
                 0,
                 "".to_string(),
             ),
-            Insn::Transaction { write } => (
+            Insn::Transaction { db, write } => (
                 "Transaction",
-                0,
+                *db as i32,
                 *write as i32,
                 0,
                 Value::build_text(""),
                 0,
-                format!("write={write}"),
+                format!("iDb={db} write={write}"),
             ),
             Insn::Goto { target_pc } => (
                 "Goto",

core/vdbe/insn.rs

@@ -330,6 +330,7 @@ pub enum Insn {
     OpenRead {
         cursor_id: CursorID,
         root_page: PageIdx,
+        db: usize,
     },
 
     /// Open a cursor for a virtual table.
@@ -459,7 +460,8 @@ pub enum Insn {
 
     /// Start a transaction.
     Transaction {
-        write: bool,
+        db: usize,   // p1
+        write: bool, // p2
     },
 
     /// Set database auto-commit mode and potentially rollback.