Modify the SQLITE_DBCONFIG_ENABLE_TRIGGER setting so that it only disables

main-schema triggers and allows TEMP trigger to continue operating.  This is
safe, since only the application (not an attacker) can add TEMP triggers.
It will also all us to disengage SQLITE_DBCONFIG_ENABLE_TRIGGER on Fossil
databases since Fossil has no main-schema triggers but does use TEMP triggers.

FossilOrigin-Name: a10c5a2503ff2998f6ee40f721aab8c9579052e535dc141bd57d10551eaea387

manifest

@@ -1,5 +1,5 @@
-C Load\senhancements\sfrom\strunk\sinto\sthe\sreturning\sbranch.
-D 2021-02-03T00:05:57.450
+C Modify\sthe\sSQLITE_DBCONFIG_ENABLE_TRIGGER\ssetting\sso\sthat\sit\sonly\sdisables\nmain-schema\striggers\sand\sallows\sTEMP\strigger\sto\scontinue\soperating.\s\sThis\sis\nsafe,\ssince\sonly\sthe\sapplication\s(not\san\sattacker)\scan\sadd\sTEMP\striggers.\nIt\swill\salso\sall\sus\sto\sdisengage\sSQLITE_DBCONFIG_ENABLE_TRIGGER\son\sFossil\ndatabases\ssince\sFossil\shas\sno\smain-schema\striggers\sbut\sdoes\suse\sTEMP\striggers.
+D 2021-02-03T00:55:34.680
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -543,7 +543,7 @@ F src/resolve.c f6761473ea4b51190fc52f8f2121498b78717266e106e7bff12849ea2d52165f
 F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
 F src/select.c 738cb746189f721f59972993c13085fa2975c4cbfd04ba26445f3b42c81237dc
 F src/shell.c.in 9ebc74e4f05cfbd0f4a36060fdaeff1da4e9af4458358722bc08c5a1ab9a0879
-F src/sqlite.h.in 0af968a1fa3c717261e1df0ed105fa7bddb4d82de7e0adb3eab49e6aa81b4de7
+F src/sqlite.h.in 8855a19f37ade8dad189a9e48233a2ebe1b46faf469c7eb0906a654e252dcc57
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 61b38c073d5e1e96a3d45271b257aef27d0d13da2bea5347692ae579475cd95e
 F src/sqliteInt.h 0fda3b2c05b1559135aa2c4ecb8e75bd2085ba4433310bbb5427d97c2d81315d
@@ -607,7 +607,7 @@ F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
 F src/tokenize.c c64c49d7c2ec4490c2fef1f24350167ba16b03b0c6cee58ad1a1d70a4325d4e9
 F src/treeview.c 4b92992176fb2caefbe06ba5bd06e0e0ebcde3d5564758da672631f17aa51cda
-F src/trigger.c a9357898b5965f579c6384b6538aa7297e3d38a132e87e1fc0e1e5b276a4cf21
+F src/trigger.c 0a242d65dd9b9822d4e990653eb4ece3557dcda01374934aa3cc1f9718d8dee3
 F src/update.c 0f5a61f0787199983530a33f6fffe4f52742f35fcdf6ccfad1078b1a8bc17723
 F src/upsert.c df8f1727d62b5987c4fd302cd4d7c0c84ae57cd65683c5a34a740dfe24039235
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
@@ -1899,7 +1899,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 2e9bd94b9ad37c7e4123b7324f2fe42d3609a65af449eb8a0064057647709a73 e4ccfac09b6fe8cc3aec29d10f4e4c83097964f29882343db52ed91f6f0dde1c
-R 189e18b39cf3d0cb3ef657405a5431b5
+P b84c7f60c2e1e7debf9f50622087f87d60c6870061d61e14e59cc1ba0775ee92
+R 02daf4bf169cb22bac4b88e2c2565d05
 U drh
-Z 8f661fe5807957ca703992c48d933956
+Z cfd272038413f78f81e2c24e00e99d6f

manifest.uuid

@@ -1 +1 @@
-b84c7f60c2e1e7debf9f50622087f87d60c6870061d61e14e59cc1ba0775ee92
+a10c5a2503ff2998f6ee40f721aab8c9579052e535dc141bd57d10551eaea387

src/sqlite.h.in

@@ -2115,7 +2115,13 @@ struct sqlite3_mem_methods {
 ** The second parameter is a pointer to an integer into which
 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
 ** following this call.  The second parameter may be a NULL pointer, in
-** which case the trigger setting is not reported back. </dd>
+** which case the trigger setting is not reported back.
+**
+** <p>Originally this option disabled all triggers.  ^(However, since
+** SQLite version 3.35.0, TEMP triggers are still allowed even if
+** this option is off.  So, in other words, this option now only disables
+** triggers in the main database schema or in the schemas of ATTACH-ed
+** databases.)^ </dd>
 **
 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>

src/trigger.c

@@ -732,31 +732,48 @@ Trigger *sqlite3TriggersExist(
   Trigger *pList = 0;
   Trigger *p;
 
-  if( (pParse->db->flags & SQLITE_EnableTrigger)!=0 ){
-    pList = sqlite3TriggerList(pParse, pTab);
-  }
+  pList = sqlite3TriggerList(pParse, pTab);
   assert( pList==0 || IsVirtual(pTab)==0 
            || (pList->bReturning && pList->pNext==0) );
-  for(p=pList; p; p=p->pNext){
-    if( p->op==op && checkColumnOverlap(p->pColumns, pChanges) ){
-      mask |= p->tr_tm;
-    }else if( p->op==TK_RETURNING ){
-      /* The first time a RETURNING trigger is seen, the "op" value tells
-      ** us what time of trigger it should be. */
-      assert( sqlite3IsToplevel(pParse) );
-      p->op = op;
-      mask |= TRIGGER_AFTER;
-      if( IsVirtual(pTab) && op!=TK_INSERT ){
-        sqlite3ErrorMsg(pParse,
-           "%s RETURNING is not available on virtual tables",
-           op==TK_DELETE ? "DELETE" : "UPDATE");
+  if( pList!=0 ){
+    p = pList;
+    if( (pParse->db->flags & SQLITE_EnableTrigger)==0
+     && pTab->pTrigger!=0
+    ){
+      /* The SQLITE_DBCONFIG_ENABLE_TRIGGER setting is off.  That means that
+      ** only TEMP triggers are allowed.  Truncate the pList so that it
+      ** includes only TEMP triggers */
+      if( pList==pTab->pTrigger ){
+        pList = 0;
+        goto exit_triggers_exist;
       }
-    }else if( p->bReturning && p->op==TK_INSERT && op==TK_UPDATE
-              && sqlite3IsToplevel(pParse) ){
-      /* Also fire a RETURNING trigger for INSERT on the UPDATE of an UPSERT */
-      mask |= TRIGGER_AFTER;
+      while( ALWAYS(p->pNext) && p->pNext!=pTab->pTrigger ) p = p->pNext;
+      p->pNext = 0;
+      p = pList;
     }
+    do{
+      if( p->op==op && checkColumnOverlap(p->pColumns, pChanges) ){
+        mask |= p->tr_tm;
+      }else if( p->op==TK_RETURNING ){
+        /* The first time a RETURNING trigger is seen, the "op" value tells
+        ** us what time of trigger it should be. */
+        assert( sqlite3IsToplevel(pParse) );
+        p->op = op;
+        mask |= TRIGGER_AFTER;
+        if( IsVirtual(pTab) && op!=TK_INSERT ){
+          sqlite3ErrorMsg(pParse,
+             "%s RETURNING is not available on virtual tables",
+             op==TK_DELETE ? "DELETE" : "UPDATE");
+        }
+      }else if( p->bReturning && p->op==TK_INSERT && op==TK_UPDATE
+                && sqlite3IsToplevel(pParse) ){
+        /* Also fire a RETURNING trigger for an UPSERT */
+        mask |= TRIGGER_AFTER;
+      }
+      p = p->pNext;
+    }while( p );
   }
+exit_triggers_exist:
   if( pMask ){
     *pMask = mask;
   }