Simplication and optimization of error message handling.

FossilOrigin-Name: 9d347f547e7ba9590b0c68edf50a14ad94a2bb92

7 files changed, 25 insertions, 25 deletions

diff --git a/src/backup.c b/src/backup.c
index 292f3f456..4a6bc7493 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -601,10 +601,10 @@ int sqlite3_backup_finish(sqlite3_backup *p){
 
   /* Set the error code of the destination database handle. */
   rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;
-  sqlite3Error(p->pDestDb, rc, 0);
-
-  /* Exit the mutexes and free the backup context structure. */
   if( p->pDestDb ){
+    sqlite3Error(p->pDestDb, rc, 0);
+
+    /* Exit the mutexes and free the backup context structure. */
     sqlite3LeaveMutexAndCloseZombie(p->pDestDb);
   }
   sqlite3BtreeLeave(p->pSrc);
diff --git a/src/main.c b/src/main.c
index 3e9f4e017..09e3bb879 100644
--- a/src/main.c
+++ b/src/main.c
@@ -987,9 +987,7 @@ void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
 #endif
 
   sqlite3Error(db, SQLITE_OK, 0); /* Deallocates any cached error strings. */
-  if( db->pErr ){
-    sqlite3ValueFree(db->pErr);
-  }
+  sqlite3ValueFree(db->pErr);
   sqlite3CloseExtensions(db);
 
   db->magic = SQLITE_MAGIC_ERROR;
@@ -1871,6 +1869,7 @@ const char *sqlite3_errmsg(sqlite3 *db){
   if( db->mallocFailed ){
     z = sqlite3ErrStr(SQLITE_NOMEM);
   }else{
+    testcase( db->pErr==0 );
     z = (char*)sqlite3_value_text(db->pErr);
     assert( !db->mallocFailed );
     if( z==0 ){
@@ -1912,8 +1911,7 @@ const void *sqlite3_errmsg16(sqlite3 *db){
   }else{
     z = sqlite3_value_text16(db->pErr);
     if( z==0 ){
-      sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
-           SQLITE_UTF8, SQLITE_STATIC);
+      sqlite3Error(db, db->errCode, sqlite3ErrStr(db->errCode));
       z = sqlite3_value_text16(db->pErr);
     }
     /* A malloc() may have failed within the call to sqlite3_value_text16()
@@ -2627,8 +2625,6 @@ static int openDatabase(
   }
 #endif
 
-  sqlite3Error(db, rc, 0);
-
   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
   ** mode.  Doing nothing at all also makes NORMAL the default.
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 1f10c31cb..8e1436efd 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3157,6 +3157,7 @@ const void *sqlite3ValueText(sqlite3_value*, u8);
 int sqlite3ValueBytes(sqlite3_value*, u8);
 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
                         void(*)(void*));
+void sqlite3ValueSetNull(sqlite3_value*);
 void sqlite3ValueFree(sqlite3_value*);
 sqlite3_value *sqlite3ValueNew(sqlite3 *);
 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
diff --git a/src/util.c b/src/util.c
index 9fa2a0fbd..362a5d897 100644
--- a/src/util.c
+++ b/src/util.c
@@ -115,18 +115,17 @@ int sqlite3Strlen30(const char *z){
 ** to NULL.
 */
 void sqlite3Error(sqlite3 *db, int err_code, const char *zFormat, ...){
-  if( db && (db->pErr || (db->pErr = sqlite3ValueNew(db))!=0) ){
-    db->errCode = err_code;
-    if( zFormat ){
-      char *z;
-      va_list ap;
-      va_start(ap, zFormat);
-      z = sqlite3VMPrintf(db, zFormat, ap);
-      va_end(ap);
-      sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);
-    }else{
-      sqlite3ValueSetStr(db->pErr, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
-    }
+  assert( db!=0 );
+  db->errCode = err_code;
+  if( zFormat && (db->pErr || (db->pErr = sqlite3ValueNew(db))!=0) ){
+    char *z;
+    va_list ap;
+    va_start(ap, zFormat);
+    z = sqlite3VMPrintf(db, zFormat, ap);
+    va_end(ap);
+    sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);
+  }else if( db->pErr ){
+    sqlite3ValueSetNull(db->pErr);
   }
 }
 
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index d51256217..ea383dffd 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -486,7 +486,7 @@ int sqlite3_step(sqlite3_stmt *pStmt){
     v->doingRerun = 1;
     assert( v->expired==0 );
   }
-  if( rc2!=SQLITE_OK && ALWAYS(v->isPrepareV2) && ALWAYS(db->pErr) ){
+  if( rc2!=SQLITE_OK ){
     /* This case occurs after failing to recompile an sql statement. 
     ** The error message from the SQL compiler has already been loaded 
     ** into the database handle. This block copies the error message 
@@ -496,6 +496,7 @@ int sqlite3_step(sqlite3_stmt *pStmt){
     ** sqlite3_errmsg() and sqlite3_errcode().
     */
     const char *zErr = (const char *)sqlite3_value_text(db->pErr); 
+    assert( zErr!=0 || db->mallocFailed );
     sqlite3DbFree(db, v->zErrMsg);
     if( !db->mallocFailed ){
       v->zErrMsg = sqlite3DbStrDup(db, zErr);
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 9e1eb581f..6344c4c8f 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -2420,6 +2420,7 @@ int sqlite3VdbeTransferError(Vdbe *p){
   if( p->zErrMsg ){
     u8 mallocFailed = db->mallocFailed;
     sqlite3BeginBenignMalloc();
+    if( db->pErr==0 ) db->pErr = sqlite3ValueNew(db);
     sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
     sqlite3EndBenignMalloc();
     db->mallocFailed = mallocFailed;
@@ -2488,8 +2489,7 @@ int sqlite3VdbeReset(Vdbe *p){
     ** to sqlite3_step(). For consistency (since sqlite3_step() was
     ** called), set the database error in this case as well.
     */
-    sqlite3Error(db, p->rc, 0);
-    sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
+    sqlite3Error(db, p->rc, p->zErrMsg ? "%s" : 0, p->zErrMsg);
     sqlite3DbFree(db, p->zErrMsg);
     p->zErrMsg = 0;
   }
diff --git a/src/vdbemem.c b/src/vdbemem.c
index d5901b439..3beccd92d 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -482,6 +482,9 @@ void sqlite3VdbeMemSetNull(Mem *pMem){
   MemSetTypeFlag(pMem, MEM_Null);
   pMem->type = SQLITE_NULL;
 }
+void sqlite3ValueSetNull(sqlite3_value *p){
+  sqlite3VdbeMemSetNull((Mem*)p); 
+}
 
 /*
 ** Delete any previous value and set the value to be a BLOB of length