If a call to sqlite3_snapshot_open() fails because the requested snapshot no

longer exists, return SQLITE_ERROR_SNAPSHOT instead of SQLITE_BUSY_SNAPSHOT.

FossilOrigin-Name: e07923128bb164efbafde29d49175b61f2ef44b2dfac5ae4ed61937945dfcf4c

3 files changed, 7 insertions, 5 deletions

diff --git a/src/main.c b/src/main.c
index b39328d23..fb7ca37c1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1329,6 +1329,7 @@ const char *sqlite3ErrName(int rc){
     switch( rc ){
       case SQLITE_OK:                 zName = "SQLITE_OK";                break;
       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
+      case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 9a611fa00..6a7c4f7e0 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -472,6 +472,7 @@ int sqlite3_exec(
 */
 #define SQLITE_ERROR_MISSING_COLLSEQ   (SQLITE_ERROR | (1<<8))
 #define SQLITE_ERROR_RETRY             (SQLITE_ERROR | (2<<8))
+#define SQLITE_ERROR_SNAPSHOT          (SQLITE_ERROR | (3<<8))
 #define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
 #define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
 #define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
@@ -9053,11 +9054,11 @@ SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
 **
 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
 ** snapshot has been overwritten by a [checkpoint]. In this case 
-** SQLITE_BUSY_SNAPSHOT is returned.
+** SQLITE_ERROR_SNAPSHOT is returned.
 **
 ** If there is already a read transaction open when this function is 
 ** invoked, then the same read transaction remains open (on the same
-** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_BUSY_SNAPSHOT
+** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
 ** is returned. If another error code - for example SQLITE_PROTOCOL or an
 ** SQLITE_IOERR error code - is returned, then the final state of the
 ** read transaction is undefined. If SQLITE_OK is returned, then the 
diff --git a/src/wal.c b/src/wal.c
index 326e25d33..8c32f3ea1 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -2795,7 +2795,7 @@ int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
         /* Check that the wal file has not been wrapped. Assuming that it has
         ** not, also check that no checkpointer has attempted to checkpoint any
         ** frames beyond pSnapshot->mxFrame. If either of these conditions are
-        ** true, return SQLITE_BUSY_SNAPSHOT. Otherwise, overwrite pWal->hdr
+        ** true, return SQLITE_ERROR_SNAPSHOT. Otherwise, overwrite pWal->hdr
         ** with *pSnapshot and set *pChanged as appropriate for opening the
         ** snapshot.  */
         if( !memcmp(pSnapshot->aSalt, pWal->hdr.aSalt, sizeof(pWal->hdr.aSalt))
@@ -2805,7 +2805,7 @@ int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
           memcpy(&pWal->hdr, pSnapshot, sizeof(WalIndexHdr));
           *pChanged = bChanged;
         }else{
-          rc = SQLITE_BUSY_SNAPSHOT;
+          rc = SQLITE_ERROR_SNAPSHOT;
         }
 
         /* Release the shared CKPT lock obtained above. */
@@ -3802,7 +3802,7 @@ int sqlite3WalSnapshotCheck(Wal *pWal, sqlite3_snapshot *pSnapshot){
     if( memcmp(pNew->aSalt, pWal->hdr.aSalt, sizeof(pWal->hdr.aSalt))
      || pNew->mxFrame<walCkptInfo(pWal)->nBackfillAttempted
     ){
-      rc = SQLITE_BUSY_SNAPSHOT;
+      rc = SQLITE_ERROR_SNAPSHOT;
       walUnlockShared(pWal, WAL_CKPT_LOCK);
     }
   }