Code simplification: ALTER TABLE ADD COLUMN always upgrades the file_format

to 4 if is not there already.  No need to upgrade to only 2 or 3 since format
4 has now been supported for over 10 years.

FossilOrigin-Name: e1d8ec85546caeca3bb7a05ad962a2aed91194ce

manifest

@@ -1,5 +1,5 @@
-C Make\ssure\severy\sco-routines\shas\sits\sown\sset\sof\stemporary\sregisters\sand\sdoes\nnot\sshare\stemporaries,\ssince\sa\sco-routine\smight\sexpect\sthe\scontent\sof\sa\ntemporary\sregister\sto\sbe\spreserved\sacross\san\sOP_Yield.\nProposed\sfix\sfor\sticket\s[d06a25c84454a].
+C Code\ssimplification:\s\sALTER\sTABLE\sADD\sCOLUMN\salways\supgrades\sthe\sfile_format\nto\s4\sif\sis\snot\sthere\salready.\s\sNo\sneed\sto\supgrade\sto\sonly\s2\sor\s3\ssince\sformat\n4\shas\snow\sbeen\ssupported\sfor\sover\s10\syears.
-D 2016-02-09T02:12:20.490
+D 2016-02-09T16:09:22.275
 F Makefile.in dac2776c84e0d533b158a9af6e57e05c4a6b19f3
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b0493f10caddb8adf992a4e6f1943141fc7c6816
@@ -284,7 +284,7 @@ F spec.template 86a4a43b99ebb3e75e6b9a735d5fd293a24e90ca
 F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 fc7ad8990fc8409983309bb80de8c811a7506786
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
-F src/alter.c d50b7dbb49a4affee951301afb76a008463e3625
+F src/alter.c 1fbb01c26c64528088f1df8015992fefda387889
 F src/analyze.c fbf0e80d83cc893734e872f932f249a056b86e11
 F src/attach.c c16c2648a577fa3def2adfa48c28901376389bc5
 F src/auth.c b56c78ebe40a2110fd361379f7e8162d23f92240
@@ -353,7 +353,7 @@ F src/shell.c dcd7a83645ef2a58ee9c6d0ea4714d877d7835c4
 F src/sqlite.h.in cf22ad1d52dca2c9862d63833e581028119aab7e
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h dfbe62ffd95b99afe2140d8c35b180d11924072d
-F src/sqliteInt.h 3aeaff9611acd790c8e76719b33db09ab885d537
+F src/sqliteInt.h b1850d30a1333de1df076eca979683f696f9d4b4
 F src/sqliteLimit.h 216557999cb45f2e3578ed53ebefe228d779cb46
 F src/status.c 70912d7be68e9e2dbc4010c93d344af61d4c59ba
 F src/table.c 51b46b2a62d1b3a959633d593b89bab5e2c9155e
@@ -439,7 +439,7 @@ F test/alias.test 4529fbc152f190268a15f9384a5651bbbabc9d87
 F test/all.test 6ff7b43c2b4b905c74dc4a813d201d0fa64c5783
 F test/alter.test 2facdddf08d0d48e75dc6cc312cd2b030f4835dd
 F test/alter2.test 7ea05c7d92ac99349a802ef7ada17294dd647060
-F test/alter3.test 49c9d9fba2b8fcdce2dedeca97bbf1f369cc548d
+F test/alter3.test b3568d11c38c4599c92f24242eda34144d78dc10
 F test/alter4.test c461150723ac957f3b2214aa0b11552cd72023ec
 F test/altermalloc.test e81ac9657ed25c6c5bb09bebfa5a047cd8e4acfc
 F test/amatch1.test b5ae7065f042b7f4c1c922933f4700add50cdb9f
@@ -1427,7 +1427,7 @@ F tool/vdbe_profile.tcl 246d0da094856d72d2c12efec03250d71639d19f
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 6eab74c9ae57676044b5bc82fa14e92fd2448008
+P ca72be8618e5d466d6f35819ca8bbd2b84269959
-R 28a5285fd29b59b5a769fa2b98c8137d
+R f95e307a4f6313b9df891047976f580b
 U drh
-Z 50a93197f1857fe46bad3c49957d1f43
+Z 5769e00c07411a2161fa568f8263dd90

manifest.uuid

@@ -1 +1 @@
-ca72be8618e5d466d6f35819ca8bbd2b84269959
+e1d8ec85546caeca3bb7a05ad962a2aed91194ce

src/alter.c

@@ -588,33 +588,6 @@ exit_rename_table:
   db->flags = savedDbFlags;
 }
 
-
-/*
-** Generate code to make sure the file format number is at least minFormat.
-** The generated code will increase the file format number if necessary.
-*/
-void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
-  Vdbe *v;
-  v = sqlite3GetVdbe(pParse);
-  /* The VDBE should have been allocated before this routine is called.
-  ** If that allocation failed, we would have quit before reaching this
-  ** point */
-  if( ALWAYS(v) ){
-    int r1 = sqlite3GetTempReg(pParse);
-    int r2 = sqlite3GetTempReg(pParse);
-    int addr1;
-    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT);
-    sqlite3VdbeUsesBtree(v, iDb);
-    sqlite3VdbeAddOp2(v, OP_Integer, minFormat, r2);
-    addr1 = sqlite3VdbeAddOp3(v, OP_Ge, r2, 0, r1);
-    sqlite3VdbeChangeP5(v, SQLITE_NOTNULL); VdbeCoverage(v);
-    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, minFormat);
-    sqlite3VdbeJumpHere(v, addr1);
-    sqlite3ReleaseTempReg(pParse, r1);
-    sqlite3ReleaseTempReg(pParse, r2);
-  }
-}
-
 /*
 ** This function is called after an "ALTER TABLE ... ADD" statement
 ** has been parsed. Argument pColDef contains the text of the new
@@ -633,9 +606,11 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
   Column *pCol;             /* The new column */
   Expr *pDflt;              /* Default value for the new column */
   sqlite3 *db;              /* The database connection; */
+  Vdbe *v = pParse->pVdbe;  /* The prepared statement under construction */
 
   db = pParse->db;
   if( pParse->nErr || db->mallocFailed ) return;
+  assert( v!=0 );
   pNew = pParse->pNewTable;
   assert( pNew );
 
@@ -725,11 +700,16 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
     db->flags = savedDbFlags;
   }
 
-  /* If the default value of the new column is NULL, then set the file
+  /* If the default value of the new column is NULL, then the file
   ** format to 2. If the default value of the new column is not NULL,
-  ** the file format becomes 3.
+  ** the file format be 3.  Back when this feature was first added
+  ** in 2006, we went to the trouble to upgrade the file format to the
+  ** minimum support values.  But 10-years on, we can assume that all
+  ** extent versions of SQLite support file-format 4, so we always and
+  ** unconditionally upgrade to 4.
   */
-  sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
+  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, 
+                    SQLITE_MAX_FILE_FORMAT);
 
   /* Reload the schema of the modified table. */
   reloadTableSchema(pParse, pTab, pTab->zName);

src/sqliteInt.h

@@ -3764,7 +3764,6 @@ void sqlite3DeleteIndexSamples(sqlite3*,Index*);
 void sqlite3DefaultRowEst(Index*);
 void sqlite3RegisterLikeFunctions(sqlite3*, int);
 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
-void sqlite3MinimumFileFormat(Parse*, int, int);
 void sqlite3SchemaClear(void *);
 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);

test/alter3.test

@@ -184,7 +184,7 @@ do_test alter3-3.2 {
 if {!$has_codec} {
   do_test alter3-3.3 {
     get_file_format
-  } {3}
+  } {4}
 }
 ifcapable schema_version {
   do_test alter3-3.4 {
@@ -220,7 +220,7 @@ do_test alter3-4.2 {
 if {!$has_codec} {
   do_test alter3-4.3 {
     get_file_format
-  } {3}
+  } {4}
 }
 ifcapable schema_version {
   do_test alter3-4.4 {
@@ -270,7 +270,7 @@ ifcapable attach {
   if {!$has_codec} {
     do_test alter3-5.5 {
       list [get_file_format test2.db] [get_file_format]
-    } {2 3}
+    } {4 4}
   }
   do_test alter3-5.6 {
     execsql {
@@ -347,19 +347,19 @@ if {!$has_codec} {
         ALTER TABLE abc ADD d DEFAULT NULL;
       }
       get_file_format
-    } {2}
+    } {4}
     do_test alter3-7.3 {
       execsql {
         ALTER TABLE abc ADD e DEFAULT 10;
       }
       get_file_format
-    } {3}
+    } {4}
     do_test alter3-7.4 {
       execsql {
         ALTER TABLE abc ADD f DEFAULT NULL;
       }
       get_file_format
-    } {3}
+    } {4}
     do_test alter3-7.5 {
       execsql {
         VACUUM;