Add support for "PRAGMA writable_schema=RESET".

FossilOrigin-Name: a51b305bd068f8d8e85b9fc38d61cdf5957f3a2ad2eb2e77015547910088e681

manifest

@@ -1,5 +1,5 @@
-C Improved\sdetection\sof\sdatabase\scorruption.
-D 2021-10-08T16:15:17.284
+C Add\ssupport\sfor\s"PRAGMA\swritable_schema=RESET".
+D 2021-10-08T16:39:33.643
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -542,7 +542,7 @@ F src/parse.y 0bd7971a7489bbf6c3726f1b50da6e508bdff8fa493e9cc3f5a96b12cbb2361e
 F src/pcache.c 084e638432c610f95aea72b8509f0845d2791293f39d1b82f0c0a7e089c3bb6b
 F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586
 F src/pcache1.c 54881292a9a5db202b2c0ac541c5e3ef9a5e8c4f1c1383adb2601d5499a60e65
-F src/pragma.c a2458437f99b356681ff3d699943e7f0eeb7ad0a00abf00df60fd8132d41f1c1
+F src/pragma.c 8d029903aac7d73ad9a304c32c98a0f65ec6fd3be37eae5d63a37900ace8e3b0
 F src/pragma.h 87330ed2fbfa2a1274de93ca0ab850fba336189228cb256089202c3b52766fad
 F src/prepare.c 8f07616db04337057b8498b72d051ee90f73c54615c2e908c05404cef1e060b7
 F src/printf.c 5901672228f305f7d493cbc4e7d76a61a5caecdbc1cd06b1f9ec42ea4265cf8d
@@ -1928,7 +1928,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P e77ac4050cf6c24118ce2af4c075f60e3eeb2dafe6d222c848bc4e541eef7172
-R 9bc76ad0c59bed7ccf95e6fe530b6c9c
+P c7fae46c8a3bd78adc5a01340eff6c1efa75f9384dc7f42cb81717b029e7c56f
+R c222db3e9e08c849b67cafc40e6de8c1
 U drh
-Z 057f03f7f6d5e1e4d7c402b7d6417858
+Z dd0d8cab0621c5c115ac8ea1cce302b4

manifest.uuid

@@ -1 +1 @@
-c7fae46c8a3bd78adc5a01340eff6c1efa75f9384dc7f42cb81717b029e7c56f
+a51b305bd068f8d8e85b9fc38d61cdf5957f3a2ad2eb2e77015547910088e681

src/pragma.c

@@ -1117,6 +1117,14 @@ void sqlite3Pragma(
       }else{
         db->flags &= ~mask;
         if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
+        if( (mask & SQLITE_WriteSchema)!=0
+         && sqlite3_stricmp(zRight, "reset")==0
+        ){
+          /* "PRAGMA writable_schema=RESET" turns schema writing off, just
+          ** like "PRAGMA writable_schema=OFF, but also causes the schema
+          ** to be reloaded. */
+          sqlite3ResetAllSchemasOfConnection(db);
+        }
       }
 
       /* Many of the flag-pragmas modify the code generated by the SQL