Add a better comment and an assert() on the code inside sqlite3CreateIndex()

that REPLACE indexes come at the end of the index list.
[forum:/forumpost/ceb51d83f7|forum post ceb51d83f7]

FossilOrigin-Name: 71e4da136bd1b5b75a699d69fbaaaec0f9dd1a87e2a9d049a55154892b06647b

diff --git a/manifest b/manifest
index bf666cca8f3044e56d6a8d76f22ba4eb049c0534..c3aea4c8e5f499d62fdba2a5f0bad2830195ca89 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sthe\s"box"\soutput\smode\sin\sthe\sshell\swhen\sstatement\sreturns\szero-column\nrows\s(for\sexample\sfrom\s"PRAGMA\sincremental_vacuum").
-D 2021-03-20T23:15:52.238
+C Add\sa\sbetter\scomment\sand\san\sassert()\son\sthe\scode\sinside\ssqlite3CreateIndex()\nthat\sREPLACE\sindexes\scome\sat\sthe\send\sof\sthe\sindex\slist.\n[forum:/forumpost/ceb51d83f7|forum\spost\sceb51d83f7]
+D 2021-03-21T17:52:47.692
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -486,7 +486,7 @@ F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
 F src/btree.c cfd2a37794532d765e235a2550ad2732924a6d06b07a3bc9f6a71750e3b3cca1
 F src/btree.h 096cc53baa58be22b02c896d1cf933c38cfc6d65f9253c1367ece8cc88a24de5
 F src/btreeInt.h 7bc15a24a02662409ebcd6aeaa1065522d14b7fda71573a2b0568b458f514ae0
-F src/build.c fec73c39d756f31d35ccbaa80fe1e040a8d675a318d4d30f41c444167bf3b860
+F src/build.c 066c44421bf7b73c6fa47f6fb0c0fcf1357c10552bcf8f3f94c6ebede581cd01
 F src/callback.c d0b853dd413255d2e337b34545e54d888ea02f20da5ad0e63585b389624c4a6c
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 2a322b9a3d75771fb4d99e0702851f4f68dda982507a0f798eefb0712969a410
@@ -1910,7 +1910,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 1805b9aaf1172e36e08271f78ebb7676bba9f3c4c28e077ee94cc31b8e7ec741
-R db4d8e4e65e8222a9a7f3090dc1a41c7
+P 34439fe3aeea7cbbc817245d39c345a7f5df7a82ac15ee4d71bb9a4d818198ed
+R 94a6696dd066ae3c18ce169901c260e2
 U drh
-Z 389fb9ea41c4380263594a1b6a568a85
+Z a74e3b4e333eec02834c3779be47be06

diff --git a/manifest.uuid b/manifest.uuid
index c96844afb9456b120e03329831b62babd1a201de..acec7ff094181cb966b1a4ab21173a3ce1483f60 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-34439fe3aeea7cbbc817245d39c345a7f5df7a82ac15ee4d71bb9a4d818198ed
\ No newline at end of file
+71e4da136bd1b5b75a699d69fbaaaec0f9dd1a87e2a9d049a55154892b06647b
\ No newline at end of file

diff --git a/src/build.c b/src/build.c
index d60cb72677840dfc92d727361a585cba35a577c8..b6faf080d5332048f5fd2a2fb9502a74e6ac1ff0 100644 (file)
--- a/src/build.c
+++ b/src/build.c
@@ -4149,7 +4149,11 @@ void sqlite3CreateIndex(
   /* Clean up before exiting */
 exit_create_index:
   if( pIndex ) sqlite3FreeIndex(db, pIndex);
-  if( pTab ){  /* Ensure all REPLACE indexes are at the end of the list */
+  if( pTab ){
+    /* Ensure all REPLACE indexes on pTab are at the end of the pIndex list.
+    ** The list was already ordered when this routine was entered, so at this
+    ** point at most a single index (the newly added index) will be out of
+    ** order.  So we have to reorder at most one index. */
     Index **ppFrom = &pTab->pIndex;
     Index *pThis;
     for(ppFrom=&pTab->pIndex; (pThis = *ppFrom)!=0; ppFrom=&pThis->pNext){
@@ -4163,6 +4167,16 @@ exit_create_index:
       }
       break;
     }
+#ifdef SQLITE_DEBUG
+    /* Verify that all REPLACE indexes really are now at the end
+    ** of the index list.  In other words, no other index type ever
+    ** comes after a REPLACE index on the list. */
+    for(pThis = pTab->pIndex; pThis; pThis=pThis->pNext){
+      assert( pThis->onError!=OE_Replace
+           || pThis->pNext==0
+           || pThis->pNext->onError==OE_Replace );
+    }
+#endif
   }
   sqlite3ExprDelete(db, pPIWhere);
   sqlite3ExprListDelete(db, pList);