Avoid repeating calls to the sqlite3_trace() callback when the same statement

is evaluted multiple times by sqlite3_step() due to an SQLITE_SCHEMA
reprepare.

FossilOrigin-Name: 39f763bfc04174ee0fe2cdf6a92b7c12f726bd1b

3 files changed, 20 insertions, 9 deletions

diff --git a/src/vdbe.c b/src/vdbe.c
index 1a3c412a7..965eec2ac 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -6075,7 +6075,10 @@ case OP_Trace: {
   char *zTrace;
   char *z;
 
-  if( db->xTrace && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0 ){
+  if( db->xTrace
+   && !p->doingRerun
+   && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
+  ){
     z = sqlite3VdbeExpandSql(p, zTrace);
     db->xTrace(db->pTraceArg, z);
     sqlite3DbFree(db, z);
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index 1f5694a59..e559bc2bd 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -273,6 +273,11 @@ struct Explain {
   char zBase[100];   /* Initial space */
 };
 
+/* A bitfield type for use inside of structures.  Always follow with :N where
+** N is the number of bits.
+*/
+typedef unsigned bft;  /* Bit Field Type */
+
 /*
 ** An instance of the virtual machine.  This structure contains the complete
 ** state of the virtual machine.
@@ -314,15 +319,16 @@ struct Vdbe {
   int pc;                 /* The program counter */
   int rc;                 /* Value to return */
   u8 errorAction;         /* Recovery action to do in case of an error */
-  u8 explain;             /* True if EXPLAIN present on SQL command */
-  u8 changeCntOn;         /* True to update the change-counter */
-  u8 expired;             /* True if the VM needs to be recompiled */
-  u8 runOnlyOnce;         /* Automatically expire on reset */
   u8 minWriteFileFormat;  /* Minimum file format for writable database files */
-  u8 inVtabMethod;        /* See comments above */
-  u8 usesStmtJournal;     /* True if uses a statement journal */
-  u8 readOnly;            /* True for read-only statements */
-  u8 isPrepareV2;         /* True if prepared with prepare_v2() */
+  bft explain:2;          /* True if EXPLAIN present on SQL command */
+  bft inVtabMethod:2;     /* See comments above */
+  bft changeCntOn:1;      /* True to update the change-counter */
+  bft expired:1;          /* True if the VM needs to be recompiled */
+  bft runOnlyOnce:1;      /* Automatically expire on reset */
+  bft usesStmtJournal:1;  /* True if uses a statement journal */
+  bft readOnly:1;         /* True for read-only statements */
+  bft isPrepareV2:1;      /* True if prepared with prepare_v2() */
+  bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
   int nChange;            /* Number of db changes made since last reset */
   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index b9a88a6ab..b48826680 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -478,10 +478,12 @@ int sqlite3_step(sqlite3_stmt *pStmt){
   }
   db = v->db;
   sqlite3_mutex_enter(db->mutex);
+  v->doingRerun = 0;
   while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
          && cnt++ < SQLITE_MAX_SCHEMA_RETRY
          && (rc2 = rc = sqlite3Reprepare(v))==SQLITE_OK ){
     sqlite3_reset(pStmt);
+    v->doingRerun = 1;
     assert( v->expired==0 );
   }
   if( rc2!=SQLITE_OK && ALWAYS(v->isPrepareV2) && ALWAYS(db->pErr) ){