lang: Add AccountNotInitialized error

lang/src/account.rs

@@ -22,6 +22,9 @@ impl<'a, T: AccountSerialize + AccountDeserialize + Owner + Clone> Account<'a, T
     /// Deserializes the given `info` into a `Account`.
     #[inline(never)]
     pub fn try_from(info: &AccountInfo<'a>) -> Result<Account<'a, T>, ProgramError> {
+        if system_program::ID.eq(info.owner) && info.lamports() == 0 {
+            return Err(ErrorCode::AccountNotInitialized.into());
+        }
         if info.owner != &T::owner() {
             return Err(ErrorCode::AccountNotProgramOwned.into());
         }
@@ -34,6 +37,9 @@ impl<'a, T: AccountSerialize + AccountDeserialize + Owner + Clone> Account<'a, T
     /// possible.
     #[inline(never)]
     pub fn try_from_unchecked(info: &AccountInfo<'a>) -> Result<Account<'a, T>, ProgramError> {
+        if system_program::ID.eq(info.owner) && info.lamports() == 0 {
+            return Err(ErrorCode::AccountNotInitialized.into());
+        }
         if info.owner != &T::owner() {
             return Err(ErrorCode::AccountNotProgramOwned.into());
         }

lang/src/error.rs

@@ -74,6 +74,8 @@ pub enum ErrorCode {
     AccountNotSigner,
     #[msg("The given account is not owned by the system program")]
     AccountNotSystemOwned,
+    #[msg("The program expected this account to be already initialized")]
+    AccountNotInitialized,
 
     // State.
     #[msg("The given state account does not have the correct address")]

ts/src/error.ts

@@ -89,6 +89,7 @@ const LangErrorCode = {
   InvalidProgramExecutable: 169,
   AccountNotSigner: 170,
   AccountNotSystemOwned: 171,
+  AccountNotInitialized: 172,
 
   // State.
   StateInvalidAddress: 180,
@@ -175,6 +176,10 @@ const LangErrorMessage = new Map([
     LangErrorCode.AccountNotSystemOwned,
     "The given account is not owned by the system program",
   ],
+  [
+    LangErrorCode.AccountNotInitialized,
+    "The program expected this account to be already initialized",
+  ],
 
   // State.
   [