Do not allow the "PRAGMA encoding" statement to change the database

encoding if TEMP content exists, or content in any other attached
database.  Formerly, encoding changes were allowed if just the main
database file was empty.  Ticket [a08879a4a476eea9].

FossilOrigin-Name: 03b003c988d27f3aa1b1e44972ee5a3c7e44ad667ec7f2b8a31d0411c66583d3

manifest

@@ -1,5 +1,5 @@
-C Fix\sthe\surifuncs.c\sextension\s(used\sfor\stesting\sand\sdebugging\sonly)\sso\sthat\nthe\ssqlite3_filename_database()\sSQL\sfunction\sand\sits\ssiblings\scorrectly\shandle\nan\sinvalid\sschema\sname\spassed\sin\sas\sthe\sargument.
-D 2020-01-14T16:50:09.276
+C Do\snot\sallow\sthe\s"PRAGMA\sencoding"\sstatement\sto\schange\sthe\sdatabase\nencoding\sif\sTEMP\scontent\sexists,\sor\scontent\sin\sany\sother\sattached\ndatabase.\s\sFormerly,\sencoding\schanges\swere\sallowed\sif\sjust\sthe\smain\ndatabase\sfile\swas\sempty.\s\sTicket\s[a08879a4a476eea9].
+D 2020-01-15T16:20:16.110
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -524,7 +524,7 @@ F src/parse.y c8d2de64db469fd56e0fa24da46cd8ec8523eb98626567d2708df371b47fdc3f
 F src/pcache.c 385ff064bca69789d199a98e2169445dc16e4291fa807babd61d4890c3b34177
 F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586
 F src/pcache1.c 6596e10baf3d8f84cc1585d226cf1ab26564a5f5caf85a15757a281ff977d51a
-F src/pragma.c 9145cc0d7309b49d383fe15deca9ab592830b8b532e7fb25e9e36b6f470cbf66
+F src/pragma.c 0d49d43b22d66397aa026db505457f6683d8a66cd0a4f9db2e6776156bda716c
 F src/pragma.h 9f86a3a3a0099e651189521c8ad03768df598974e7bbdc21c7f9bb6125592fbd
 F src/prepare.c 6049beb71385f017af6fc320d2c75a4e50b75e280c54232442b785fbb83df057
 F src/printf.c 9be6945837c839ba57837b4bc3af349eba630920fa5532aa518816defe42a7d4
@@ -848,7 +848,7 @@ F test/e_walckpt.test 28c371a6bb5e5fe7f31679c1df1763a19d19e8a0
 F test/e_walhook.test 01b494287ba9e60b70f6ebf3c6c62e0ffe01788e344a4846b08e5de0b344cb66
 F test/emptytable.test a38110becbdfa6325cd65cb588dca658cd885f62
 F test/enc.test e54531cd6bf941ee6760be041dff19a104c7acea
-F test/enc2.test 83437a79ba1545a55fb549309175c683fb334473
+F test/enc2.test 848bf05f15b011719f478dddb7b5e9aea35e39e457493cba4c4eef75d849a5ec
 F test/enc3.test 6807f7a7740a00361ca8d0ccd66bc60c8dc5f2b6
 F test/enc4.test c8f1ce3618508fd0909945beb8b8831feef2c020
 F test/eqp.test 84879b63e3110552bf8ce648a3507dc3ceb72109ecec83c2aef0db37a27f6382
@@ -1857,7 +1857,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 54bf04811951db6c894f272f870e3e41f8f5e05a25c1115efbbdbd0d8bba54be
-R ef60df967e796bd9bfc273160d5104d4
+P 3d7434a9d85dae9135473d1c58c22ac01a282e654807aa10be9b39f127291594
+R 8a9a1a9f3b4869ab1515f6774449d079
 U drh
-Z 6fa8f0dab0c264087d10e9adb2b33207
+Z 4597b9944f2bad0f6e2f950727bac08b

manifest.uuid

@@ -1 +1 @@
-3d7434a9d85dae9135473d1c58c22ac01a282e654807aa10be9b39f127291594
+03b003c988d27f3aa1b1e44972ee5a3c7e44ad667ec7f2b8a31d0411c66583d3

src/pragma.c

@@ -1824,10 +1824,17 @@ void sqlite3Pragma(
       ** will be overwritten when the schema is next loaded. If it does not
       ** already exists, it will be created to use the new encoding value.
       */
-      if( 
-        !(DbHasProperty(db, 0, DB_SchemaLoaded)) || 
-        DbHasProperty(db, 0, DB_Empty) 
-      ){
+      int canChangeEnc = 1;  /* True if allowed to change the encoding */
+      int i;                 /* For looping over all attached databases */
+      for(i=0; i<db->nDb; i++){
+        if( db->aDb[i].pBt!=0
+         && DbHasProperty(db,i,DB_SchemaLoaded)
+         && !DbHasProperty(db,i,DB_Empty)
+        ){
+          canChangeEnc = 0;
+        }
+      }
+      if( canChangeEnc ){
         for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
           if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){
             SCHEMA_ENC(db) = ENC(db) =

test/enc2.test

@@ -13,7 +13,6 @@
 # various suported unicode encodings (UTF-8, UTF-16, UTF-16le and
 # UTF-16be).
 #
-# $Id: enc2.test,v 1.29 2007/10/09 08:29:32 danielk1977 Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -552,4 +551,17 @@ do_test enc2-10.1 {
   }
 } {t1 t2}
 
+# 2020-01-15 ticket a08879a4a476eea9
+# Do not allow a database connection encoding change unless *all*
+# attached databases are empty.
+#
+reset_db
+do_execsql_test enc2-11.10 {
+  PRAGMA encoding=UTF8;
+  CREATE TEMP TABLE t1(x);
+  INSERT INTO t1 VALUES('this is a test');
+  PRAGMA encoding=UTF16;
+  SELECT * FROM t1;
+} {{this is a test}}
+
 finish_test