Merging upstream version 3.46.1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

15 files changed, 202 insertions, 198 deletions

diff --git a/ext/consio/console_io.c b/ext/consio/console_io.c
index 3e2f556..3fa613b 100755
--- a/ext/consio/console_io.c
+++ b/ext/consio/console_io.c
@@ -54,11 +54,6 @@
 #endif
 
 #if CIO_WIN_WC_XLATE
-/* Character used to represent a known-incomplete UTF-8 char group (�) */
-static WCHAR cBadGroup = 0xfffd;
-#endif
-
-#if CIO_WIN_WC_XLATE
 static HANDLE handleOfFile(FILE *pf){
   int fileDesc = _fileno(pf);
   union { intptr_t osfh; HANDLE fh; } fid = {
diff --git a/ext/expert/expert1.test b/ext/expert/expert1.test
index c456c30..72c4fd7 100644
--- a/ext/expert/expert1.test
+++ b/ext/expert/expert1.test
@@ -465,6 +465,13 @@ do_execsql_test 5.3 {
   t2 t2_idx_0001295b {100 20 5}
 }
 
+do_catchsql_test 5.4 {
+  SELECT sqlite_expert_rem(123, 123);
+} {1 {no such function: sqlite_expert_rem}}
+do_catchsql_test 5.5 {
+  SELECT sqlite_expert_sample();
+} {1 {no such function: sqlite_expert_sample}}
+
 if 0 {
 do_test expert1-6.0 {
   catchcmd :memory: {
diff --git a/ext/expert/sqlite3expert.c b/ext/expert/sqlite3expert.c
index 276c2cc..b59a597 100644
--- a/ext/expert/sqlite3expert.c
+++ b/ext/expert/sqlite3expert.c
@@ -626,7 +626,7 @@ static int expertFilter(
   pCsr->pData = 0;
   if( rc==SQLITE_OK ){
     rc = idxPrintfPrepareStmt(pExpert->db, &pCsr->pData, &pVtab->base.zErrMsg,
-        "SELECT * FROM main.%Q WHERE sample()", pVtab->pTab->zName
+        "SELECT * FROM main.%Q WHERE sqlite_expert_sample()", pVtab->pTab->zName
     );
   }
 
@@ -1500,7 +1500,7 @@ struct IdxRemCtx {
 };
 
 /*
-** Implementation of scalar function rem().
+** Implementation of scalar function sqlite_expert_rem().
 */
 static void idxRemFunc(
   sqlite3_context *pCtx,
@@ -1513,7 +1513,7 @@ static void idxRemFunc(
   assert( argc==2 );
 
   iSlot = sqlite3_value_int(argv[0]);
-  assert( iSlot<=p->nSlot );
+  assert( iSlot<p->nSlot );
   pSlot = &p->aSlot[iSlot];
 
   switch( pSlot->eType ){
@@ -1624,7 +1624,8 @@ static int idxPopulateOneStat1(
     const char *zName = (const char*)sqlite3_column_text(pIndexXInfo, 0);
     const char *zColl = (const char*)sqlite3_column_text(pIndexXInfo, 1);
     zCols = idxAppendText(&rc, zCols, 
-        "%sx.%Q IS rem(%d, x.%Q) COLLATE %s", zComma, zName, nCol, zName, zColl
+        "%sx.%Q IS sqlite_expert_rem(%d, x.%Q) COLLATE %s", 
+        zComma, zName, nCol, zName, zColl
     );
     zOrder = idxAppendText(&rc, zOrder, "%s%d", zComma, ++nCol);
   }
@@ -1757,13 +1758,13 @@ static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
 
   if( rc==SQLITE_OK ){
     sqlite3 *dbrem = (p->iSample==100 ? p->db : p->dbv);
-    rc = sqlite3_create_function(
-        dbrem, "rem", 2, SQLITE_UTF8, (void*)pCtx, idxRemFunc, 0, 0
+    rc = sqlite3_create_function(dbrem, "sqlite_expert_rem", 
+        2, SQLITE_UTF8, (void*)pCtx, idxRemFunc, 0, 0
     );
   }
   if( rc==SQLITE_OK ){
-    rc = sqlite3_create_function(
-        p->db, "sample", 0, SQLITE_UTF8, (void*)&samplectx, idxSampleFunc, 0, 0
+    rc = sqlite3_create_function(p->db, "sqlite_expert_sample", 
+        0, SQLITE_UTF8, (void*)&samplectx, idxSampleFunc, 0, 0
     );
   }
 
@@ -1815,6 +1816,9 @@ static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
     rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_schema", 0, 0, 0);
   }
 
+  sqlite3_create_function(p->db, "sqlite_expert_rem", 2, SQLITE_UTF8, 0,0,0,0);
+  sqlite3_create_function(p->db, "sqlite_expert_sample", 0,SQLITE_UTF8,0,0,0,0);
+
   sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
   return rc;
 }
diff --git a/ext/fts5/fts5_expr.c b/ext/fts5/fts5_expr.c
index 05c1b59..960a4d4 100644
--- a/ext/fts5/fts5_expr.c
+++ b/ext/fts5/fts5_expr.c
@@ -324,7 +324,11 @@ int sqlite3Fts5ExprNew(
   }
 
   sqlite3_free(sParse.apPhrase);
-  *pzErr = sParse.zErr;
+  if( 0==*pzErr ){
+    *pzErr = sParse.zErr;
+  }else{
+    sqlite3_free(sParse.zErr);
+  }
   return sParse.rc;
 }
 
@@ -2452,6 +2456,7 @@ Fts5ExprNode *sqlite3Fts5ParseImplicitAnd(
     assert( pRight->eType==FTS5_STRING 
         || pRight->eType==FTS5_TERM 
         || pRight->eType==FTS5_EOF 
+        || (pRight->eType==FTS5_AND && pParse->bPhraseToAnd) 
     );
 
     if( pLeft->eType==FTS5_AND ){
diff --git a/ext/fts5/fts5_main.c b/ext/fts5/fts5_main.c
index f609f7f..837ea40 100644
--- a/ext/fts5/fts5_main.c
+++ b/ext/fts5/fts5_main.c
@@ -1700,6 +1700,7 @@ static int fts5UpdateMethod(
         rc = SQLITE_ERROR;
       }else{
         rc = fts5SpecialDelete(pTab, apVal);
+        bUpdateOrDelete = 1;
       }
     }else{
       rc = fts5SpecialInsert(pTab, z, apVal[2 + pConfig->nCol + 1]);
@@ -2874,14 +2875,16 @@ int sqlite3Fts5GetTokenizer(
   if( pMod==0 ){
     assert( nArg>0 );
     rc = SQLITE_ERROR;
-    *pzErr = sqlite3_mprintf("no such tokenizer: %s", azArg[0]);
+    if( pzErr ) *pzErr = sqlite3_mprintf("no such tokenizer: %s", azArg[0]);
   }else{
     rc = pMod->x.xCreate(
         pMod->pUserData, (azArg?&azArg[1]:0), (nArg?nArg-1:0), &pConfig->pTok
     );
     pConfig->pTokApi = &pMod->x;
     if( rc!=SQLITE_OK ){
-      if( pzErr ) *pzErr = sqlite3_mprintf("error in tokenizer constructor");
+      if( pzErr && rc!=SQLITE_NOMEM ){
+        *pzErr = sqlite3_mprintf("error in tokenizer constructor");
+      }
     }else{
       pConfig->ePattern = sqlite3Fts5TokenizerPattern(
           pMod->x.xCreate, pConfig->pTok
@@ -2975,17 +2978,23 @@ static int fts5IntegrityMethod(
 
   assert( pzErr!=0 && *pzErr==0 );
   UNUSED_PARAM(isQuick);
+  assert( pTab->p.pConfig->pzErrmsg==0 );
+  pTab->p.pConfig->pzErrmsg = pzErr;
   rc = sqlite3Fts5StorageIntegrity(pTab->pStorage, 0);
-  if( (rc&0xff)==SQLITE_CORRUPT ){
-    *pzErr = sqlite3_mprintf("malformed inverted index for FTS5 table %s.%s",
-                zSchema, zTabname);
-     rc = (*pzErr) ? SQLITE_OK : SQLITE_NOMEM;
-  }else if( rc!=SQLITE_OK ){
-    *pzErr = sqlite3_mprintf("unable to validate the inverted index for"
-                             " FTS5 table %s.%s: %s",
-                zSchema, zTabname, sqlite3_errstr(rc));
+  if( *pzErr==0 && rc!=SQLITE_OK ){
+    if( (rc&0xff)==SQLITE_CORRUPT ){
+      *pzErr = sqlite3_mprintf("malformed inverted index for FTS5 table %s.%s",
+          zSchema, zTabname);
+      rc = (*pzErr) ? SQLITE_OK : SQLITE_NOMEM;
+    }else{
+      *pzErr = sqlite3_mprintf("unable to validate the inverted index for"
+          " FTS5 table %s.%s: %s",
+          zSchema, zTabname, sqlite3_errstr(rc));
+    }
   }
+
   sqlite3Fts5IndexCloseReader(pTab->p.pIndex);
+  pTab->p.pConfig->pzErrmsg = 0;
 
   return rc;
 }
diff --git a/ext/fts5/fts5_tokenize.c b/ext/fts5/fts5_tokenize.c
index f120561..2200e78 100644
--- a/ext/fts5/fts5_tokenize.c
+++ b/ext/fts5/fts5_tokenize.c
@@ -79,7 +79,7 @@ static int fts5AsciiCreate(
       int i;
       memset(p, 0, sizeof(AsciiTokenizer));
       memcpy(p->aTokenChar, aAsciiTokenChar, sizeof(aAsciiTokenChar));
-      for(i=0; rc==SQLITE_OK && i<nArg; i+=2){
+      for(i=0; rc==SQLITE_OK && i<nArg-1; i+=2){
         const char *zArg = azArg[i+1];
         if( 0==sqlite3_stricmp(azArg[i], "tokenchars") ){
           fts5AsciiAddExceptions(p, zArg, 1);
@@ -90,6 +90,7 @@ static int fts5AsciiCreate(
           rc = SQLITE_ERROR;
         }
       }
+      if( rc==SQLITE_OK && i<nArg ) rc = SQLITE_ERROR;
       if( rc!=SQLITE_OK ){
         fts5AsciiDelete((Fts5Tokenizer*)p);
         p = 0;
@@ -381,17 +382,16 @@ static int fts5UnicodeCreate(
       }
 
       /* Search for a "categories" argument */
-      for(i=0; rc==SQLITE_OK && i<nArg; i+=2){
+      for(i=0; rc==SQLITE_OK && i<nArg-1; i+=2){
         if( 0==sqlite3_stricmp(azArg[i], "categories") ){
           zCat = azArg[i+1];
         }
       }
-
       if( rc==SQLITE_OK ){
         rc = unicodeSetCategories(p, zCat);
       }
 
-      for(i=0; rc==SQLITE_OK && i<nArg; i+=2){
+      for(i=0; rc==SQLITE_OK && i<nArg-1; i+=2){
         const char *zArg = azArg[i+1];
         if( 0==sqlite3_stricmp(azArg[i], "remove_diacritics") ){
           if( (zArg[0]!='0' && zArg[0]!='1' && zArg[0]!='2') || zArg[1] ){
@@ -416,6 +416,7 @@ static int fts5UnicodeCreate(
           rc = SQLITE_ERROR;
         }
       }
+      if( i<nArg && rc==SQLITE_OK ) rc = SQLITE_ERROR;
 
     }else{
       rc = SQLITE_NOMEM;
@@ -1298,7 +1299,7 @@ static int fts5TriCreate(
     int i;
     pNew->bFold = 1;
     pNew->iFoldParam = 0;
-    for(i=0; rc==SQLITE_OK && i<nArg; i+=2){
+    for(i=0; rc==SQLITE_OK && i<nArg-1; i+=2){
       const char *zArg = azArg[i+1];
       if( 0==sqlite3_stricmp(azArg[i], "case_sensitive") ){
         if( (zArg[0]!='0' && zArg[0]!='1') || zArg[1] ){
@@ -1316,6 +1317,7 @@ static int fts5TriCreate(
         rc = SQLITE_ERROR;
       }
     }
+    if( i<nArg && rc==SQLITE_OK ) rc = SQLITE_ERROR;
 
     if( pNew->iFoldParam!=0 && pNew->bFold==0 ){
       rc = SQLITE_ERROR;
diff --git a/ext/fts5/test/fts5aux.test b/ext/fts5/test/fts5aux.test
index 5569f48..7963006 100644
--- a/ext/fts5/test/fts5aux.test
+++ b/ext/fts5/test/fts5aux.test
@@ -377,4 +377,28 @@ do_catchsql_test 12.3.3 {
   SELECT fts5_collist(t1, 1) FROM t1('one AND two');
 } {0 1}
 
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 13.1 {
+  CREATE VIRTUAL TABLE t1 USING fts5(a, tokenize=ascii);
+  INSERT INTO t1 VALUES('a b c'), ('d e f');
+  PRAGMA integrity_check;
+} {ok}
+
+do_catchsql_test 13.2 {
+  SELECT highlight(t1, 0, '[', ']') FROM t1
+} {0 {{a b c} {d e f}}}
+
+do_execsql_test 13.3 {
+  PRAGMA writable_schema = 1;
+  UPDATE sqlite_schema SET sql = 'CREATE VIRTUAL TABLE t1 USING fts5(a, tokenize=blah)'
+  WHERE name = 't1';
+}
+
+db close
+sqlite3 db test.db
+do_catchsql_test 13.4 {
+  SELECT highlight(t1, 0, '[', ']') FROM t1
+} {1 {no such tokenizer: blah}}
+
 finish_test
diff --git a/ext/fts5/test/fts5integrity.test b/ext/fts5/test/fts5integrity.test
index 1bb3675..5ed659b 100644
--- a/ext/fts5/test/fts5integrity.test
+++ b/ext/fts5/test/fts5integrity.test
@@ -380,5 +380,32 @@ do_execsql_test 12.3 {
 } {ok}
 
 
+#-------------------------------------------------------------------
+reset_db
+do_execsql_test 13.1 {
+  CREATE VIRTUAL TABLE t1 USING fts5(a, tokenize=ascii);
+  INSERT INTO t1 VALUES('a b c'), ('d e f');
+  PRAGMA integrity_check;
+} {ok}
+
+db close
+sqlite3 db test.db
+do_catchsql_test 13.2 {
+  PRAGMA integrity_check;
+} {0 ok}
+
+do_execsql_test 13.3 {
+  PRAGMA writable_schema = 1;
+  UPDATE sqlite_schema SET sql = 'CREATE VIRTUAL TABLE t1 USING fts5(a, tokenize=blah)'
+  WHERE name = 't1';
+}
+
+db close
+sqlite3 db test.db
+breakpoint
+do_catchsql_test 13.4 {
+  PRAGMA integrity_check;
+} {1 {no such tokenizer: blah}}
+
 
 finish_test
diff --git a/ext/fts5/test/fts5secure8.test b/ext/fts5/test/fts5secure8.test
index 8ceb963..0216bb6 100644
--- a/ext/fts5/test/fts5secure8.test
+++ b/ext/fts5/test/fts5secure8.test
@@ -42,6 +42,22 @@ do_execsql_test 1.2 {
   PRAGMA integrity_check;
 } {ok}
 
+do_execsql_test 2.0 {
+  CREATE VIRTUAL TABLE xyz USING fts5 (
+  	name,
+        content=''
+  );
+
+  INSERT INTO xyz(xyz, rank) VALUES('secure-delete', 1);
+  INSERT INTO xyz (rowid, name) VALUES(1, 'A');
+  INSERT INTO xyz (rowid, name) VALUES(2, 'A');
+  INSERT INTO xyz(xyz, rowid, name) VALUES('delete', 2, 'A');
+}
+
+do_execsql_test 2.1 {
+  pragma quick_check;
+} {ok}
+
 
 
 
diff --git a/ext/fts5/test/fts5tokenizer2.test b/ext/fts5/test/fts5tokenizer2.test
index bdabd53..52b3032 100644
--- a/ext/fts5/test/fts5tokenizer2.test
+++ b/ext/fts5/test/fts5tokenizer2.test
@@ -85,5 +85,25 @@ do_execsql_test 1.7 {
   SELECT highlight(t1, 0, '>', '<') FROM t1('BB mess');
 } {AAdont>BBmess<}
 
+# 2024-08-06 https://sqlite.org/forum/forumpost/171bcc2bcd
+# Error handling of tokenize= arguments.
+#
+foreach {n tkz} {
+  1  {ascii none}
+  2  {unicode61 none}
+  3  {porter none}
+  4  {trigram none}
+  5  {ascii none 0}
+  6  {unicode61 none 0}
+  7  {porter none 0}
+  8  {trigram none 0}
+} {
+  db eval {DROP TABLE IF EXISTS t2;}
+  do_catchsql_test 2.$n "
+     DROP TABLE IF EXISTS t2;
+     CREATE VIRTUAL TABLE t2 USING fts5(a,b,c,tokenize='$tkz');
+  " {1 {error in tokenizer constructor}}
+}
+
 
 finish_test
diff --git a/ext/fts5/test/fts5trigram.test b/ext/fts5/test/fts5trigram.test
index 351c059..7526866 100644
--- a/ext/fts5/test/fts5trigram.test
+++ b/ext/fts5/test/fts5trigram.test
@@ -69,6 +69,9 @@ do_execsql_test 2.0 {
   INSERT INTO t1 VALUES('abcdefghijklm');
   INSERT INTO t1 VALUES('กรุงเทพมหานคร');
 }
+do_catchsql_test 2.0.1 {
+  CREATE VIRTUAL TABLE t2 USING fts5(z, tokenize='trigram case_sensitive');
+} {1 {error in tokenizer constructor}}
 
 foreach {tn s res} {
   1 abc           "(abc)defghijklm"
@@ -206,7 +209,7 @@ do_execsql_test 7.0 {
       (20, "жираф.png"), 
       (30, "cat.png"), 
       (40, "кот.png"), 
-      (50, "misic-🎵-.mp3");
+      (50, "misic-🎵-.mp3");
 }
 do_execsql_test 7.1 {
   SELECT rowid FROM f WHERE +filename GLOB '*ир*';
diff --git a/ext/fts5/test/fts5trigram2.test b/ext/fts5/test/fts5trigram2.test
index f5beae5..395d899 100644
--- a/ext/fts5/test/fts5trigram2.test
+++ b/ext/fts5/test/fts5trigram2.test
@@ -21,6 +21,9 @@ do_execsql_test 1.0 "
   INSERT INTO t1 VALUES('abc\u0303defghijklm');
   INSERT INTO t1 VALUES('a\u0303b\u0303c\u0303defghijklm');
 "
+do_catchsql_test 1.0.1 {
+  CREATE VIRTUAL TABLE t2 USING fts5(z, tokenize='trigram remove_diacritics');
+} {1 {error in tokenizer constructor}}
 
 do_execsql_test 1.1 {
   SELECT highlight(t1, 0, '(', ')') FROM t1('abc');
diff --git a/ext/recover/sqlite3recover.c b/ext/recover/sqlite3recover.c
index 1d858c0..afa1ae8 100644
--- a/ext/recover/sqlite3recover.c
+++ b/ext/recover/sqlite3recover.c
@@ -363,8 +363,8 @@ static int recoverError(
   va_start(ap, zFmt);
   if( zFmt ){
     z = sqlite3_vmprintf(zFmt, ap);
-    va_end(ap);
   }
+  va_end(ap);
   sqlite3_free(p->zErrMsg);
   p->zErrMsg = z;
   p->errCode = errCode;
diff --git a/ext/wasm/api/sqlite3-opfs-async-proxy.js b/ext/wasm/api/sqlite3-opfs-async-proxy.js
index e671094..3e2b20f 100644
--- a/ext/wasm/api/sqlite3-opfs-async-proxy.js
+++ b/ext/wasm/api/sqlite3-opfs-async-proxy.js
@@ -87,35 +87,6 @@ const installAsyncProxy = function(){
   const log =    (...args)=>logImpl(2, ...args);
   const warn =   (...args)=>logImpl(1, ...args);
   const error =  (...args)=>logImpl(0, ...args);
-  const metrics = Object.create(null);
-  metrics.reset = ()=>{
-    let k;
-    const r = (m)=>(m.count = m.time = m.wait = 0);
-    for(k in state.opIds){
-      r(metrics[k] = Object.create(null));
-    }
-    let s = metrics.s11n = Object.create(null);
-    s = s.serialize = Object.create(null);
-    s.count = s.time = 0;
-    s = metrics.s11n.deserialize = Object.create(null);
-    s.count = s.time = 0;
-  };
-  metrics.dump = ()=>{
-    let k, n = 0, t = 0, w = 0;
-    for(k in state.opIds){
-      const m = metrics[k];
-      n += m.count;
-      t += m.time;
-      w += m.wait;
-      m.avgTime = (m.count && m.time) ? (m.time / m.count) : 0;
-    }
-    console.log(globalThis?.location?.href,
-                "metrics for",globalThis?.location?.href,":\n",
-                metrics,
-                "\nTotal of",n,"op(s) for",t,"ms",
-                "approx",w,"ms spent waiting on OPFS APIs.");
-    console.log("Serialization metrics:",metrics.s11n);
-  };
 
   /**
      __openFiles is a map of sqlite3_file pointers (integers) to
@@ -265,23 +236,34 @@ const installAsyncProxy = function(){
       this.name = 'GetSyncHandleError';
     }
   };
+
+  /**
+     Attempts to find a suitable SQLITE_xyz result code for Error
+     object e. Returns either such a translation or rc if if it does
+     not know how to translate the exception.
+  */
   GetSyncHandleError.convertRc = (e,rc)=>{
-    if(1){
-      return (
-        e instanceof GetSyncHandleError
-          && ((e.cause.name==='NoModificationAllowedError')
-              /* Inconsistent exception.name from Chrome/ium with the
-                 same exception.message text: */
-              || (e.cause.name==='DOMException'
-                  && 0===e.cause.message.indexOf('Access Handles cannot')))
-      ) ? (
-        /*console.warn("SQLITE_BUSY",e),*/
-        state.sq3Codes.SQLITE_BUSY
-      ) : rc;
-    }else{
-      return rc;
+    if( e instanceof GetSyncHandleError ){
+      if( e.cause.name==='NoModificationAllowedError'
+        /* Inconsistent exception.name from Chrome/ium with the
+           same exception.message text: */
+          || (e.cause.name==='DOMException'
+              && 0===e.cause.message.indexOf('Access Handles cannot')) ){
+        return state.sq3Codes.SQLITE_BUSY;
+      }else if( 'NotFoundError'===e.cause.name ){
+        /**
+           Maintenance reminder: SQLITE_NOTFOUND, though it looks like
+           a good match, has different semantics than NotFoundError
+           and is not suitable here.
+        */
+        return state.sq3Codes.SQLITE_CANTOPEN;
+      }
+    }else if( 'NotFoundError'===e?.name ){
+      return state.sq3Codes.SQLITE_CANTOPEN;
     }
-  }
+    return rc;
+  };
+
   /**
      Returns the sync access handle associated with the given file
      handle object (which must be a valid handle object, as created by
@@ -348,37 +330,6 @@ const installAsyncProxy = function(){
   };
 
   /**
-     We track 2 different timers: the "metrics" timer records how much
-     time we spend performing work. The "wait" timer records how much
-     time we spend waiting on the underlying OPFS timer. See the calls
-     to mTimeStart(), mTimeEnd(), wTimeStart(), and wTimeEnd()
-     throughout this file to see how they're used.
-  */
-  const __mTimer = Object.create(null);
-  __mTimer.op = undefined;
-  __mTimer.start = undefined;
-  const mTimeStart = (op)=>{
-    __mTimer.start = performance.now();
-    __mTimer.op = op;
-    //metrics[op] || toss("Maintenance required: missing metrics for",op);
-    ++metrics[op].count;
-  };
-  const mTimeEnd = ()=>(
-    metrics[__mTimer.op].time += performance.now() - __mTimer.start
-  );
-  const __wTimer = Object.create(null);
-  __wTimer.op = undefined;
-  __wTimer.start = undefined;
-  const wTimeStart = (op)=>{
-    __wTimer.start = performance.now();
-    __wTimer.op = op;
-    //metrics[op] || toss("Maintenance required: missing metrics for",op);
-  };
-  const wTimeEnd = ()=>(
-    metrics[__wTimer.op].wait += performance.now() - __wTimer.start
-  );
-
-  /**
      Gets set to true by the 'opfs-async-shutdown' command to quit the
      wait loop. This is only intended for debugging purposes: we cannot
      inspect this file's state while the tight waitLoop() is running and
@@ -388,37 +339,24 @@ const installAsyncProxy = function(){
 
   /**
      Asynchronous wrappers for sqlite3_vfs and sqlite3_io_methods
-     methods, as well as helpers like mkdir(). Maintenance reminder:
-     members are in alphabetical order to simplify finding them.
+     methods, as well as helpers like mkdir().
   */
   const vfsAsyncImpls = {
-    'opfs-async-metrics': async ()=>{
-      mTimeStart('opfs-async-metrics');
-      metrics.dump();
-      storeAndNotify('opfs-async-metrics', 0);
-      mTimeEnd();
-    },
     'opfs-async-shutdown': async ()=>{
       flagAsyncShutdown = true;
       storeAndNotify('opfs-async-shutdown', 0);
     },
     mkdir: async (dirname)=>{
-      mTimeStart('mkdir');
       let rc = 0;
-      wTimeStart('mkdir');
       try {
         await getDirForFilename(dirname+"/filepart", true);
       }catch(e){
         state.s11n.storeException(2,e);
         rc = state.sq3Codes.SQLITE_IOERR;
-      }finally{
-        wTimeEnd();
       }
       storeAndNotify('mkdir', rc);
-      mTimeEnd();
     },
     xAccess: async (filename)=>{
-      mTimeStart('xAccess');
       /* OPFS cannot support the full range of xAccess() queries
          sqlite3 calls for. We can essentially just tell if the file
          is accessible, but if it is then it's automatically writable
@@ -431,26 +369,20 @@ const installAsyncProxy = function(){
          accessible, non-0 means not accessible.
       */
       let rc = 0;
-      wTimeStart('xAccess');
       try{
         const [dh, fn] = await getDirForFilename(filename);
         await dh.getFileHandle(fn);
       }catch(e){
         state.s11n.storeException(2,e);
         rc = state.sq3Codes.SQLITE_IOERR;
-      }finally{
-        wTimeEnd();
       }
       storeAndNotify('xAccess', rc);
-      mTimeEnd();
     },
     xClose: async function(fid/*sqlite3_file pointer*/){
       const opName = 'xClose';
-      mTimeStart(opName);
       __implicitLocks.delete(fid);
       const fh = __openFiles[fid];
       let rc = 0;
-      wTimeStart(opName);
       if(fh){
         delete __openFiles[fid];
         await closeSyncHandle(fh);
@@ -462,15 +394,11 @@ const installAsyncProxy = function(){
         state.s11n.serialize();
         rc = state.sq3Codes.SQLITE_NOTFOUND;
       }
-      wTimeEnd();
       storeAndNotify(opName, rc);
-      mTimeEnd();
     },
     xDelete: async function(...args){
-      mTimeStart('xDelete');
       const rc = await vfsAsyncImpls.xDeleteNoWait(...args);
       storeAndNotify('xDelete', rc);
-      mTimeEnd();
     },
     xDeleteNoWait: async function(filename, syncDir = 0, recursive = false){
       /* The syncDir flag is, for purposes of the VFS API's semantics,
@@ -486,7 +414,6 @@ const installAsyncProxy = function(){
          is false.
       */
       let rc = 0;
-      wTimeStart('xDelete');
       try {
         while(filename){
           const [hDir, filenamePart] = await getDirForFilename(filename, false);
@@ -502,14 +429,11 @@ const installAsyncProxy = function(){
         state.s11n.storeException(2,e);
         rc = state.sq3Codes.SQLITE_IOERR_DELETE;
       }
-      wTimeEnd();
       return rc;
     },
     xFileSize: async function(fid/*sqlite3_file pointer*/){
-      mTimeStart('xFileSize');
       const fh = __openFiles[fid];
       let rc = 0;
-      wTimeStart('xFileSize');
       try{
         const sz = await (await getSyncHandle(fh,'xFileSize')).getSize();
         state.s11n.serialize(Number(sz));
@@ -518,19 +442,15 @@ const installAsyncProxy = function(){
         rc = GetSyncHandleError.convertRc(e,state.sq3Codes.SQLITE_IOERR);
       }
       await releaseImplicitLock(fh);
-      wTimeEnd();
       storeAndNotify('xFileSize', rc);
-      mTimeEnd();
     },
     xLock: async function(fid/*sqlite3_file pointer*/,
                           lockType/*SQLITE_LOCK_...*/){
-      mTimeStart('xLock');
       const fh = __openFiles[fid];
       let rc = 0;
       const oldLockType = fh.xLock;
       fh.xLock = lockType;
       if( !fh.syncHandle ){
-        wTimeStart('xLock');
         try {
           await getSyncHandle(fh,'xLock');
           __implicitLocks.delete(fid);
@@ -539,18 +459,14 @@ const installAsyncProxy = function(){
           rc = GetSyncHandleError.convertRc(e,state.sq3Codes.SQLITE_IOERR_LOCK);
           fh.xLock = oldLockType;
         }
-        wTimeEnd();
       }
       storeAndNotify('xLock',rc);
-      mTimeEnd();
     },
     xOpen: async function(fid/*sqlite3_file pointer*/, filename,
                           flags/*SQLITE_OPEN_...*/,
                           opfsFlags/*OPFS_...*/){
       const opName = 'xOpen';
-      mTimeStart(opName);
       const create = (state.sq3Codes.SQLITE_OPEN_CREATE & flags);
-      wTimeStart('xOpen');
       try{
         let hDir, filenamePart;
         try {
@@ -558,8 +474,6 @@ const installAsyncProxy = function(){
         }catch(e){
           state.s11n.storeException(1,e);
           storeAndNotify(opName, state.sq3Codes.SQLITE_NOTFOUND);
-          mTimeEnd();
-          wTimeEnd();
           return;
         }
         if( state.opfsFlags.OPFS_UNLINK_BEFORE_OPEN & opfsFlags ){
@@ -571,7 +485,6 @@ const installAsyncProxy = function(){
           }
         }
         const hFile = await hDir.getFileHandle(filenamePart, {create});
-        wTimeEnd();
         const fh = Object.assign(Object.create(null),{
           fid: fid,
           filenameAbs: filename,
@@ -586,76 +499,50 @@ const installAsyncProxy = function(){
         fh.releaseImplicitLocks =
           (opfsFlags & state.opfsFlags.OPFS_UNLOCK_ASAP)
           || state.opfsFlags.defaultUnlockAsap;
-        if(0 /* this block is modelled after something wa-sqlite
-                does but it leads to immediate contention on journal files.
-                Update: this approach reportedly only works for DELETE journal
-                mode. */
-           && (0===(flags & state.sq3Codes.SQLITE_OPEN_MAIN_DB))){
-          /* sqlite does not lock these files, so go ahead and grab an OPFS
-             lock. */
-          fh.xLock = "xOpen"/* Truthy value to keep entry from getting
-                               flagged as auto-locked. String value so
-                               that we can easily distinguish is later
-                               if needed. */;
-          await getSyncHandle(fh,'xOpen');
-        }
         __openFiles[fid] = fh;
         storeAndNotify(opName, 0);
       }catch(e){
-        wTimeEnd();
         error(opName,e);
         state.s11n.storeException(1,e);
         storeAndNotify(opName, state.sq3Codes.SQLITE_IOERR);
       }
-      mTimeEnd();
     },
     xRead: async function(fid/*sqlite3_file pointer*/,n,offset64){
-      mTimeStart('xRead');
       let rc = 0, nRead;
       const fh = __openFiles[fid];
       try{
-        wTimeStart('xRead');
         nRead = (await getSyncHandle(fh,'xRead')).read(
           fh.sabView.subarray(0, n),
           {at: Number(offset64)}
         );
-        wTimeEnd();
         if(nRead < n){/* Zero-fill remaining bytes */
           fh.sabView.fill(0, nRead, n);
           rc = state.sq3Codes.SQLITE_IOERR_SHORT_READ;
         }
       }catch(e){
-        if(undefined===nRead) wTimeEnd();
         error("xRead() failed",e,fh);
         state.s11n.storeException(1,e);
         rc = GetSyncHandleError.convertRc(e,state.sq3Codes.SQLITE_IOERR_READ);
       }
       await releaseImplicitLock(fh);
       storeAndNotify('xRead',rc);
-      mTimeEnd();
     },
     xSync: async function(fid/*sqlite3_file pointer*/,flags/*ignored*/){
-      mTimeStart('xSync');
       const fh = __openFiles[fid];
       let rc = 0;
       if(!fh.readOnly && fh.syncHandle){
         try {
-          wTimeStart('xSync');
           await fh.syncHandle.flush();
         }catch(e){
           state.s11n.storeException(2,e);
           rc = state.sq3Codes.SQLITE_IOERR_FSYNC;
         }
-        wTimeEnd();
       }
       storeAndNotify('xSync',rc);
-      mTimeEnd();
     },
     xTruncate: async function(fid/*sqlite3_file pointer*/,size){
-      mTimeStart('xTruncate');
       let rc = 0;
       const fh = __openFiles[fid];
-      wTimeStart('xTruncate');
       try{
         affirmNotRO('xTruncate', fh);
         await (await getSyncHandle(fh,'xTruncate')).truncate(size);
@@ -665,33 +552,25 @@ const installAsyncProxy = function(){
         rc = GetSyncHandleError.convertRc(e,state.sq3Codes.SQLITE_IOERR_TRUNCATE);
       }
       await releaseImplicitLock(fh);
-      wTimeEnd();
       storeAndNotify('xTruncate',rc);
-      mTimeEnd();
     },
     xUnlock: async function(fid/*sqlite3_file pointer*/,
                             lockType/*SQLITE_LOCK_...*/){
-      mTimeStart('xUnlock');
       let rc = 0;
       const fh = __openFiles[fid];
       if( state.sq3Codes.SQLITE_LOCK_NONE===lockType
           && fh.syncHandle ){
-        wTimeStart('xUnlock');
         try { await closeSyncHandle(fh) }
         catch(e){
           state.s11n.storeException(1,e);
           rc = state.sq3Codes.SQLITE_IOERR_UNLOCK;
         }
-        wTimeEnd();
       }
       storeAndNotify('xUnlock',rc);
-      mTimeEnd();
     },
     xWrite: async function(fid/*sqlite3_file pointer*/,n,offset64){
-      mTimeStart('xWrite');
       let rc;
       const fh = __openFiles[fid];
-      wTimeStart('xWrite');
       try{
         affirmNotRO('xWrite', fh);
         rc = (
@@ -705,9 +584,7 @@ const installAsyncProxy = function(){
         rc = GetSyncHandleError.convertRc(e,state.sq3Codes.SQLITE_IOERR_WRITE);
       }
       await releaseImplicitLock(fh);
-      wTimeEnd();
       storeAndNotify('xWrite',rc);
-      mTimeEnd();
     }
   }/*vfsAsyncImpls*/;
 
@@ -741,8 +618,6 @@ const installAsyncProxy = function(){
       }
     };
     state.s11n.deserialize = function(clear=false){
-      ++metrics.s11n.deserialize.count;
-      const t = performance.now();
       const argc = viewU8[0];
       const rc = argc ? [] : null;
       if(argc){
@@ -767,12 +642,9 @@ const installAsyncProxy = function(){
       }
       if(clear) viewU8[0] = 0;
       //log("deserialize:",argc, rc);
-      metrics.s11n.deserialize.time += performance.now() - t;
       return rc;
     };
     state.s11n.serialize = function(...args){
-      const t = performance.now();
-      ++metrics.s11n.serialize.count;
       if(args.length){
         //log("serialize():",args);
         const typeIds = [];
@@ -803,7 +675,6 @@ const installAsyncProxy = function(){
       }else{
         viewU8[0] = 0;
       }
-      metrics.s11n.serialize.time += performance.now() - t;
     };
 
     state.s11n.storeException = state.asyncS11nExceptions
@@ -885,7 +756,6 @@ const installAsyncProxy = function(){
               }
             });
             initS11n();
-            metrics.reset();
             log("init state",state);
             wPost('opfs-async-inited');
             waitLoop();
@@ -898,9 +768,6 @@ const installAsyncProxy = function(){
               waitLoop();
             }
             break;
-          case 'opfs-async-metrics':
-            metrics.dump();
-            break;
       }
     };
     wPost('opfs-async-loaded');
diff --git a/ext/wasm/api/sqlite3-vfs-opfs.c-pp.js b/ext/wasm/api/sqlite3-vfs-opfs.c-pp.js
index 4c654c3..5b74e78 100644
--- a/ext/wasm/api/sqlite3-vfs-opfs.c-pp.js
+++ b/ext/wasm/api/sqlite3-vfs-opfs.c-pp.js
@@ -392,6 +392,7 @@ const installOpfsVfs = function callee(options){
       'SQLITE_ACCESS_EXISTS',
       'SQLITE_ACCESS_READWRITE',
       'SQLITE_BUSY',
+      'SQLITE_CANTOPEN',
       'SQLITE_ERROR',
       'SQLITE_IOERR',
       'SQLITE_IOERR_ACCESS',
@@ -444,7 +445,7 @@ const installOpfsVfs = function callee(options){
       OPFS_UNLINK_BEFORE_OPEN: 0x02,
       /**
          If true, any async routine which implicitly acquires a sync
-         access handle (i.e. an OPFS lock) will release that locks at
+         access handle (i.e. an OPFS lock) will release that lock at
          the end of the call which acquires it. If false, such
          "autolocks" are not released until the VFS is idle for some
          brief amount of time.
@@ -471,9 +472,22 @@ const installOpfsVfs = function callee(options){
       Atomics.notify(state.sabOPView, state.opIds.whichOp)
       /* async thread will take over here */;
       const t = performance.now();
-      Atomics.wait(state.sabOPView, state.opIds.rc, -1)
-      /* When this wait() call returns, the async half will have
-         completed the operation and reported its results. */;
+      while('not-equal'!==Atomics.wait(state.sabOPView, state.opIds.rc, -1)){
+        /*
+          The reason for this loop is buried in the details of a long
+          discussion at:
+
+          https://github.com/sqlite/sqlite-wasm/issues/12
+
+          Summary: in at least one browser flavor, under high loads,
+          the wait()/notify() pairings can get out of sync. Calling
+          wait() here until it returns 'not-equal' gets them back in
+          sync.
+        */
+      }
+      /* When the above wait() call returns 'not-equal', the async
+         half will have completed the operation and reported its results
+         in the state.opIds.rc slot of the SAB. */
       const rc = Atomics.load(state.sabOPView, state.opIds.rc);
       metrics[op].wait += performance.now() - t;
       if(rc && state.asyncS11nExceptions){
@@ -720,9 +734,18 @@ const installOpfsVfs = function callee(options){
            involve an inherent race condition. For the time being,
            pending a better solution, we simply report whether the
            given pFile is open.
+
+           Update 2024-06-12: based on forum discussions, this
+           function now always sets pOut to 0 (false):
+
+           https://sqlite.org/forum/forumpost/a2f573b00cda1372
         */
-        const f = __openFiles[pFile];
-        wasm.poke(pOut, f.lockType ? 1 : 0, 'i32');
+        if(1){
+          wasm.poke(pOut, 0, 'i32');
+        }else{
+          const f = __openFiles[pFile];
+          wasm.poke(pOut, f.lockType ? 1 : 0, 'i32');
+        }
         return 0;
       },
       xClose: function(pFile){
@@ -738,7 +761,6 @@ const installOpfsVfs = function callee(options){
         return rc;
       },
       xDeviceCharacteristics: function(pFile){
-        //debug("xDeviceCharacteristics(",pFile,")");
         return capi.SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN;
       },
       xFileControl: function(pFile, opId, pArg){