Modify the drop column code to handle WITHOUT ROWID tables for which a single column appears more than once in the primary key.

FossilOrigin-Name: e0d2507021c5a04016c442f954b542c0920678737ae7c710eb8ac50d6337db1c

manifest

@@ -1,5 +1,5 @@
-C Restructure\sa\sloop\sin\swindow.c\sto\savoid\shitting\san\sassert()\sfollowing\san\sOOM.\sdbsqlfuzz\stest\scase\s6ef74a9659de87e9be3d8694ad062c448aa7ef1d.
+C Modify\sthe\sdrop\scolumn\scode\sto\shandle\sWITHOUT\sROWID\stables\sfor\swhich\sa\ssingle\scolumn\sappears\smore\sthan\sonce\sin\sthe\sprimary\skey.
-D 2021-04-06T18:40:27.012
+D 2021-04-06T21:20:39.072
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -476,7 +476,7 @@ F spec.template 86a4a43b99ebb3e75e6b9a735d5fd293a24e90ca
 F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 fc7ad8990fc8409983309bb80de8c811a7506786
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
-F src/alter.c ee335771956c1b674ec5f3f943cf7179f877accf208c498271c72b4ea8d16409
+F src/alter.c 14d5d9ba332de515c6e2f729e728426cdd6f5683cdc356ba6b6e3444e1ed210e
 F src/analyze.c 01c6c6765cb4d40b473b71d85535093730770bb186f2f473abac25f07fcdee5c
 F src/attach.c 9cbe761e464025694df8e6f6ee4d9f41432c3a255ca9443ccbb4130eeb87cf72
 F src/auth.c 08954fdc4cc2da5264ba5b75cfd90b67a6fc7d1710a02ccf917c38eadec77853
@@ -649,7 +649,7 @@ F test/alterauth.test 63442ba61ceb0c1eeb63aac1f4f5cebfa509d352276059d27106ae256b
 F test/alterauth2.test 381b1ab603c9ef96314a3158528ea17f7964449385a28eeaf8191120b2e24a8d
 F test/altercol.test b11fa1b131e80ab5b6ecfb3b725fb0419c14ca6efba5adb57aeabfc9baa0c8f3
 F test/altercorrupt.test 584d707a80e106952d6382790c8919bcf9f0db678ed3a1c09fd98b7f9d1d3a10
-F test/alterdropcol.test 596623cb8a72d9570bfb8417b0f302810efe007873796f03c17a9e9ff28dade1
+F test/alterdropcol.test fdfac0280099a5e19ae5bf29bcd49f6fe13186398d6803b070b724ea4d9c6306
 F test/alterdropcol2.test 527fce683b200d620f560f666c44ae33e22728e990a10a48a543280dfd4b4d41
 F test/alterlegacy.test f38c6d06cda39e1f7b955bbce57f2e3ef5b7cb566d3d1234502093e228c15811
 F test/altermalloc.test 167a47de41b5c638f5f5c6efb59784002b196fff70f98d9b4ed3cd74a3fb80c9
@@ -1912,7 +1912,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 55cad6f628a4313c6652b36474c3397f097ac5c2503ae94605c030a54dc40916
+P 887c19a15ba60a5dc375dda7e289d476ba24d4adb38086a013df9709b88f32a7
-R b502ee77b1b130709f2eeb35bafb000a
+R 83038b920e6d418d2a4a2058a89a8d4f
 U dan
-Z 2d22ad4166814d461d32beca1b8c9ac2
+Z 2293d8c2e3c5f4a9a58f9cff85d615f1

manifest.uuid

@@ -1 +1 @@
-887c19a15ba60a5dc375dda7e289d476ba24d4adb38086a013df9709b88f32a7
+e0d2507021c5a04016c442f954b542c0920678737ae7c710eb8ac50d6337db1c

src/alter.c

@@ -2096,18 +2096,25 @@ void sqlite3AlterDropColumn(Parse *pParse, SrcList *pSrc, Token *pName){
     sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite);
     addr = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
     reg = ++pParse->nMem;
-    pParse->nMem += pTab->nCol;
     if( HasRowid(pTab) ){
       sqlite3VdbeAddOp2(v, OP_Rowid, iCur, reg);
+      pParse->nMem += pTab->nCol;
     }else{
       pPk = sqlite3PrimaryKeyIndex(pTab);
+      pParse->nMem += pPk->nColumn;
+      for(i=0; i<pPk->nKeyCol; i++){
+        sqlite3VdbeAddOp3(v, OP_Column, iCur, i, reg+i+1);
+      }
+      nField = pPk->nKeyCol;
     }
+    regRec = ++pParse->nMem;
     for(i=0; i<pTab->nCol; i++){
       if( i!=iCol && (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0 ){
         int regOut;
         if( pPk ){
           int iPos = sqlite3TableColumnToIndex(pPk, i);
           int iColPos = sqlite3TableColumnToIndex(pPk, iCol);
+          if( iPos<pPk->nKeyCol ) continue;
           regOut = reg+1+iPos-(iPos>iColPos);
         }else{
           regOut = reg+1+nField;
@@ -2116,7 +2123,6 @@ void sqlite3AlterDropColumn(Parse *pParse, SrcList *pSrc, Token *pName){
         nField++;
       }
     }
-    regRec = reg + pTab->nCol;
     sqlite3VdbeAddOp3(v, OP_MakeRecord, reg+1, nField, regRec);
     if( pPk ){
       sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iCur, regRec, reg+1, pPk->nKeyCol);

test/alterdropcol.test

@@ -276,4 +276,21 @@ do_catchsql_test 6.1 {
   ALTER TABLE t2 DROP COLUMN z;
 } {1 {database disk image is malformed}}
 
+# 2021-04-06 dbsqlfuzz crash-331c5c29bb76257b198f1318eef3288f9624c8ce
+reset_db
+do_execsql_test 7.0 {
+  CREATE TABLE t1(a, b, c, PRIMARY KEY(a COLLATE nocase, a)) WITHOUT ROWID;
+  INSERT INTO t1 VALUES(1, 2, 3);
+  INSERT INTO t1 VALUES(4, 5, 6);
+}
+do_execsql_test 7.1 {
+  ALTER TABLE t1 DROP COLUMN c;                
+}
+do_execsql_test 7.2 {
+  SELECT sql FROM sqlite_schema;
+} {{CREATE TABLE t1(a, b, PRIMARY KEY(a COLLATE nocase, a)) WITHOUT ROWID}}
+do_execsql_test 7.3 {
+  SELECT * FROM t1;
+} {1 2 4 5}
+
 finish_test