Fix a bug in changeset generation code.

FossilOrigin-Name: 825df75ba453c853953e17ec29653e11c46f92bb

ext/session/session2.test

@@ -112,6 +112,11 @@ do_common_sql {
   CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));
 }
 
+# Execute each of the following blocks of SQL on database [db1]. Collect
+# changes using a session object. Apply the resulting changeset to
+# database [db2]. Then check that the contents of the two databases are
+# identical.
+#
 foreach {tn sql} {
   1 { INSERT INTO t1 VALUES(1, 2) } 
 
@@ -150,7 +155,23 @@ foreach {tn sql} {
     DELETE FROM t1 WHERE (rowid%3)==0;
   }
 
+  8 {
+    BEGIN;
+      INSERT INTO t1 SELECT randomblob(32), randomblob(32) FROM t1;
+    ROLLBACK;
+  }
+  9 {
+    BEGIN;
+      UPDATE t1 SET b = 'xxx';
+    ROLLBACK;
+  }
+  10 {
+    BEGIN;
+      DELETE FROM t1 WHERE 1;
+    ROLLBACK;
+  }
 } {
+if {$tn==9} breakpoint
   do_then_apply_sql $sql
   do_test $tn { compare_db db db2 } {}
 }

ext/session/sqlite3session.c

@@ -1115,6 +1115,7 @@ static void sessionAppendUpdate(
   if( *pRc==SQLITE_OK ){
     SessionBuffer buf2 = {0,0,0}; /* Buffer to accumulate new.* record in */
     int bNoop = 1;                /* Set to zero if any values are modified */
+    int nRewind = pBuf->nBuf;     /* Set to zero if any values are modified */
     int i;                        /* Used to iterate through columns */
     u8 *pCsr = p->aRecord;        /* Used to iterate through old.* values */
 
@@ -1180,11 +1181,11 @@ static void sessionAppendUpdate(
     }
 
     if( bNoop ){
-      pBuf->nBuf -= (1 + sqlite3_column_count(pStmt));
+      pBuf->nBuf = nRewind;
     }else{
       sessionAppendBlob(pBuf, buf2.aBuf, buf2.nBuf, pRc);
-      sqlite3_free(buf2.aBuf);
     }
+    sqlite3_free(buf2.aBuf);
   }
 }
 
@@ -1314,10 +1315,10 @@ int sqlite3session_changeset(
     if( pTab->nEntry ){
       int nCol = pTab->nCol;      /* Local copy of member variable */
       u8 *abPK = pTab->abPK;      /* Local copy of member variable */
-      int i;
-      sqlite3_stmt *pStmt = 0;
-      int bNoop = 1;
-      int nRewind = buf.nBuf;
+      int i;                      /* Used to iterate through hash buckets */
+      sqlite3_stmt *pSel = 0;     /* SELECT statement to query table pTab */
+      int nRewind = buf.nBuf;     /* Initial size of write buffer */
+      int nNoop;                  /* Size of buffer after writing tbl header */
 
       /* Write a table header */
       sessionAppendByte(&buf, 'T', &rc);
@@ -1326,44 +1327,43 @@ int sqlite3session_changeset(
 
       /* Build and compile a statement to execute: */
       if( rc==SQLITE_OK ){
-        rc = sessionSelectStmt(db, pTab->zName, nCol, pTab->azCol, abPK,&pStmt);
+        rc = sessionSelectStmt(db, pTab->zName, nCol, pTab->azCol, abPK, &pSel);
       }
 
-      if( rc==SQLITE_OK && nCol!=sqlite3_column_count(pStmt) ){
+      if( rc==SQLITE_OK && nCol!=sqlite3_column_count(pSel) ){
         rc = SQLITE_SCHEMA;
       }
 
+      nNoop = buf.nBuf;
       for(i=0; i<pTab->nChange; i++){
         SessionChange *p;         /* Used to iterate through changes */
 
         for(p=pTab->apChange[i]; rc==SQLITE_OK && p; p=p->pNext){
-          rc = sessionSelectBind(pStmt, nCol, abPK, p->aRecord, p->nRecord);
+          rc = sessionSelectBind(pSel, nCol, abPK, p->aRecord, p->nRecord);
           if( rc==SQLITE_OK ){
-            if( sqlite3_step(pStmt)==SQLITE_ROW ){
+            if( sqlite3_step(pSel)==SQLITE_ROW ){
               int iCol;
               if( p->bInsert ){
                 sessionAppendByte(&buf, SQLITE_INSERT, &rc);
                 for(iCol=0; iCol<nCol; iCol++){
-                  sessionAppendCol(&buf, pStmt, iCol, &rc);
+                  sessionAppendCol(&buf, pSel, iCol, &rc);
                 }
               }else{
-                sessionAppendUpdate(&buf, pStmt, p, abPK, &rc);
+                sessionAppendUpdate(&buf, pSel, p, abPK, &rc);
               }
-              bNoop = 0;
             }else if( !p->bInsert ){
               /* A DELETE change */
               sessionAppendByte(&buf, SQLITE_DELETE, &rc);
               sessionAppendBlob(&buf, p->aRecord, p->nRecord, &rc);
-              bNoop = 0;
             }
-            rc = sqlite3_reset(pStmt);
+            rc = sqlite3_reset(pSel);
           }
         }
       }
 
-      sqlite3_finalize(pStmt);
+      sqlite3_finalize(pSel);
 
-      if( bNoop ){
+      if( buf.nBuf==nNoop ){
         buf.nBuf = nRewind;
       }
     }

manifest

@@ -1,5 +1,5 @@
-C Move\ssession1.test\sfrom\stest/\sto\sext/session/.
-D 2011-03-19T17:07:58
+C Fix\sa\sbug\sin\schangeset\sgeneration\scode.
+D 2011-03-19T18:46:16
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 27701a1653595a1f2187dc61c8117e00a6c1d50f
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -99,9 +99,9 @@ F ext/rtree/rtree_util.tcl 06aab2ed5b826545bf215fff90ecb9255a8647ea
 F ext/rtree/sqlite3rtree.h 1af0899c63a688e272d69d8e746f24e76f10a3f0
 F ext/rtree/tkt3363.test 142ab96eded44a3615ec79fba98c7bde7d0f96de
 F ext/rtree/viewrtree.tcl eea6224b3553599ae665b239bd827e182b466024
-F ext/session/session1.test 3f982c74ee4ba97069917cc35aae25b4ed858e6a w test/session1.test
-F ext/session/session2.test 61c7ee56d158ab614b058b860508c85db2985810
-F ext/session/sqlite3session.c 55ec4205c7a12e417c38743d81e229a31a0f7e25
+F ext/session/session1.test 3f982c74ee4ba97069917cc35aae25b4ed858e6a
+F ext/session/session2.test 09cbe57d949a315c68fb59822314990fd0e2af33
+F ext/session/sqlite3session.c 4cb15010040b093e452e6de52e8b5a9161032ebf
 F ext/session/sqlite3session.h 9551c002efd5fde07c52994c6b592308e0df2d6a
 F ext/session/test_session.c 2559ef68e421c7fb83e2c19ef08a17343b70d535
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895
@@ -921,7 +921,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 6e5907e14d3316d56313243c4f8ce8f14d0858fc
-R 611730f89810ada9d2f188c5b6da861b
+P c4436a936ab302aec3b7f41a4552f69ad5815744
+R 633c4c2a52a8f04fd2ba1fea02dc8ad5
 U dan
-Z a6a229bf3ddc4c217d0e04afae66c6a2
+Z 046a676deaa5ff1f82305a84f859a0a7

manifest.uuid

@@ -1 +1 @@
-c4436a936ab302aec3b7f41a4552f69ad5815744
+825df75ba453c853953e17ec29653e11c46f92bb