From be53500356d2b2006671defd9b59a4fef9846257 Mon Sep 17 00:00:00 2001
From: dan <dan@noemail.net>
Date: Fri, 1 Apr 2011 15:15:58 +0000
Subject: [PATCH] Ensure that it is not possible to add a column to a system
 table using ALTER TABLE.

FossilOrigin-Name: d9707ef8dcd29667b6d366897f6ad02c87aa0041
---
 manifest        | 16 ++++++++--------
 manifest.uuid   |  2 +-
 src/alter.c     | 28 ++++++++++++++++++++++------
 test/alter.test | 19 +++++++++++++++++++
 4 files changed, 50 insertions(+), 15 deletions(-)

diff --git a/manifest b/manifest
index 54e008c6ee..179b8e01d2 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Merge\sthe\sANALYZE-index\senhancement\sinto\strunk.
-D 2011-04-01T14:26:14.943
+C Ensure\sthat\sit\sis\snot\spossible\sto\sadd\sa\scolumn\sto\sa\ssystem\stable\susing\sALTER\sTABLE.
+D 2011-04-01T15:15:58.380
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 27701a1653595a1f2187dc61c8117e00a6c1d50f
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -114,7 +114,7 @@ F spec.template 86a4a43b99ebb3e75e6b9a735d5fd293a24e90ca
 F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 6be1ad09113570e1fc8dcaff84c9b0b337db5ffc
 F sqlite3.pc.in ae6f59a76e862f5c561eb32a380228a02afc3cad
-F src/alter.c 6a0c176e64a34929a4436048066a84ef4f1445b3
+F src/alter.c 280f5c04b11b492703a342222b3de0a999445280
 F src/analyze.c d0a673d303f611690fc7a3293aaefed57cccc5c8
 F src/attach.c 438ea6f6b5d5961c1f49b737f2ce0f14ce7c6877
 F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
@@ -248,7 +248,7 @@ F src/where.c 176574bfeee13775761ce56416f773b0ec115d3f
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/alias.test 4529fbc152f190268a15f9384a5651bbbabc9d87
 F test/all.test 51756962d522e474338e9b2ebb26e7364d4aa125
-F test/alter.test 15f9224868b290d6bf7a63f31437f31aee070636
+F test/alter.test 4e47fb9ea59348b88fce4e8bb49de530128b104c
 F test/alter2.test 75f731508f1bf27ba09a6075c66cd02216ba464b
 F test/alter3.test 8677e48d95536f7a6ed86a1a774744dadcc22b07
 F test/alter4.test 1e5dd6b951e9f65ca66422edff02e56df82dd403
@@ -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 7a6d05dfbc36310683dd51a280e9283cef4f9056 365896cb0868fa476e3b4f5a965a1344a2914cc2
-R 7c9526ecaff8bc8061319f5def8d1613
-U drh
-Z 1a31242492e35c93d42d83f1529d907f
+P 7e237aea22084416d02b89d5223de4e1ca76882d
+R 68179f8f20bd7e83c0daf30e8b4b7cff
+U dan
+Z 07da6539f8d6e81dde928bab49d2b3fe
diff --git a/manifest.uuid b/manifest.uuid
index 86580230d4..e4175092fa 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-7e237aea22084416d02b89d5223de4e1ca76882d
\ No newline at end of file
+d9707ef8dcd29667b6d366897f6ad02c87aa0041
\ No newline at end of file
diff --git a/src/alter.c b/src/alter.c
index 1534fdf69e..aa3fa929f8 100644
--- a/src/alter.c
+++ b/src/alter.c
@@ -370,6 +370,22 @@ static void reloadTableSchema(Parse *pParse, Table *pTab, const char *zName){
 #endif
 }
 
+/*
+** Parameter zName is the name of a table that is about to be altered
+** (either with ALTER TABLE ... RENAME TO or ALTER TABLE ... ADD COLUMN).
+** If the table is a system table, this function leaves an error message
+** in pParse->zErr (system tables may not be altered) and returns non-zero.
+**
+** Or, if zName is not a system table, zero is returned.
+*/
+static int isSystemTable(Parse *pParse, const char *zName){
+  if( sqlite3Strlen30(zName)>6 && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){
+    sqlite3ErrorMsg(pParse, "table %s may not be altered", zName);
+    return 1;
+  }
+  return 0;
+}
+
 /*
 ** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" 
 ** command. 
@@ -420,14 +436,11 @@ void sqlite3AlterRenameTable(
   /* Make sure it is not a system table being altered, or a reserved name
   ** that the table is being renamed to.
   */
-  if( sqlite3Strlen30(pTab->zName)>6 
-   && 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7)
-  ){
-    sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
+  if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
     goto exit_rename_table;
   }
-  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
-    goto exit_rename_table;
+  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto
+    exit_rename_table;
   }
 
 #ifndef SQLITE_OMIT_VIEW
@@ -759,6 +772,9 @@ void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
     sqlite3ErrorMsg(pParse, "Cannot add a column to a view");
     goto exit_begin_add_column;
   }
+  if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){
+    goto exit_begin_add_column;
+  }
 
   assert( pTab->addColOffset>0 );
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
diff --git a/test/alter.test b/test/alter.test
index bf7cf00624..d4b72a6ae8 100644
--- a/test/alter.test
+++ b/test/alter.test
@@ -840,4 +840,23 @@ do_test alter-14.2 {
 } {1 {Cannot add a PRIMARY KEY column}}
 
 
+#-------------------------------------------------------------------------
+# Test that it is not possible to use ALTER TABLE on any system table.
+#
+set system_table_list {1 sqlite_master}
+catchsql ANALYZE
+ifcapable analyze { lappend system_table_list 2 sqlite_stat1 }
+ifcapable stat2   { lappend system_table_list 3 sqlite_stat2 }
+
+foreach {tn tbl} $system_table_list {
+  do_test alter-15.$tn.1 {
+    catchsql "ALTER TABLE $tbl RENAME TO xyz"
+  } [list 1 "table $tbl may not be altered"]
+
+  do_test alter-15.$tn.2 {
+    catchsql "ALTER TABLE $tbl ADD COLUMN xyz"
+  } [list 1 "table $tbl may not be altered"]
+}
+
+
 finish_test