From a25d478ea81f47b57c4658ffb88c55a5cc2f9c3d Mon Sep 17 00:00:00 2001
From: larrybr <larrybr@noemail.net>
Date: Sun, 24 Sep 2023 19:00:00 +0000
Subject: [PATCH] Give expert ability to deal with custom collations.

FossilOrigin-Name: ac1dc1b6ded0e43acb5b2b707110f767f7bdb5cecdb6b28a982db174ae233d37
---
 ext/expert/sqlite3expert.c | 21 ++++++++++++++++++++-
 manifest                   | 15 ++++++---------
 manifest.uuid              |  2 +-
 3 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/ext/expert/sqlite3expert.c b/ext/expert/sqlite3expert.c
index a57664800b..e93a7c19cb 100644
--- a/ext/expert/sqlite3expert.c
+++ b/ext/expert/sqlite3expert.c
@@ -1818,9 +1818,20 @@ static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
   return rc;
 }
 
+/*
+** Define and possibly pretend to use a useless collation sequence.
+** This pretense allows expert to accept SQL using custom collations.
+*/
+int dummyCompare(void*, int, const void*, int, const void*){
+  return 0;
+}
+/* And a callback to register above upon actual need */
+void useDummyCS(void *, sqlite3 *db, int etr, const char *zName){
+  sqlite3_create_collation_v2(db, zName, etr, 0, dummyCompare, 0);
+}
+
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) \
   && !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
-
 /*
 ** dummy functions for no-op implementation of UDFs during expert's work
 */
@@ -1919,6 +1930,10 @@ sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErrmsg){
     idxFinalize(&rc, pSql);
   }
 
+  /* Allow custom collations to be dealt with through prepare. */
+  if( rc==SQLITE_OK ) rc = sqlite3_collation_needed(pNew->dbm,0,useDummyCS);
+  if( rc==SQLITE_OK ) rc = sqlite3_collation_needed(pNew->dbv,0,useDummyCS);
+
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) \
   && !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
   /* Register UDFs from database [db] with [dbm] and [dbv]. */
@@ -1990,6 +2005,10 @@ int sqlite3_expert_sql(
 
   while( rc==SQLITE_OK && zStmt && zStmt[0] ){
     sqlite3_stmt *pStmt = 0;
+    /* Ensure that the provided statement compiles against user's DB. */
+    rc = idxPrepareStmt(p->db, &pStmt, pzErr, zStmt);
+    if( rc!=SQLITE_OK ) break;
+    sqlite3_finalize(pStmt);
     rc = sqlite3_prepare_v2(p->dbv, zStmt, -1, &pStmt, &zStmt);
     if( rc==SQLITE_OK ){
       if( pStmt ){
diff --git a/manifest b/manifest
index 907d8cda73..30e935a72c 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Give\sexpert\sability\sto\sdeal\swith\sUDFs.
-D 2023-09-22T14:20:45.507
+C Give\sexpert\sability\sto\sdeal\swith\scustom\scollations.
+D 2023-09-24T19:00:00.954
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -53,7 +53,7 @@ F ext/async/sqlite3async.h 46b47c79357b97ad85d20d2795942c0020dc20c532114a4980828
 F ext/expert/README.md b321c2762bb93c18ea102d5a5f7753a4b8bac646cb392b3b437f633caf2020c3
 F ext/expert/expert.c d548d603a4cc9e61f446cc179c120c6713511c413f82a4a32b1e1e69d3f086a4
 F ext/expert/expert1.test 95b00567ce0775126a1b788af2d055255014714ecfddc97913864d2f9266e583
-F ext/expert/sqlite3expert.c 295015a89169dd56210d41ee12cc4666120ae7cd6fdc3059dda6c5f6f25a942d
+F ext/expert/sqlite3expert.c b07038a5e312f8e5f81dce7c7885bff8ae76e6bd5d63a2cea524c329a0987733
 F ext/expert/sqlite3expert.h ca81efc2679a92373a13a3e76a6138d0310e32be53d6c3bfaedabd158ea8969b
 F ext/expert/test_expert.c d56c194b769bdc90cf829a14c9ecbc1edca9c850b837a4d0b13be14095c32a72
 F ext/fts3/README.content b9078d0843a094d86af0d48dffbff13c906702b4c3558012e67b9c7cc3bf59ee
@@ -2121,11 +2121,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 04a333f5faf6b90592f1f69889ac6c28949955e186f39037cd639480b06feae8
-R 60a342742d52c0b762612e7ca689cb9f
-T *branch * expert-udfs
-T *sym-expert-udfs *
-T -sym-trunk *
+P 3406b05b4f57901f64f9b5fc83fe0250b827ae7f342c2026818dab0840aafd23
+R 4fd35ee51e3295c4798887f6f81483f9
 U larrybr
-Z 571810c2a50aa1c1d6fa7a9dfd64586a
+Z 0102b81fd083e10463436403edc18206
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 008a0e7cc5..874ad43499 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3406b05b4f57901f64f9b5fc83fe0250b827ae7f342c2026818dab0840aafd23
\ No newline at end of file
+ac1dc1b6ded0e43acb5b2b707110f767f7bdb5cecdb6b28a982db174ae233d37
\ No newline at end of file