From 43bc88bbe8430023f4a9f64b2f165086e3f8cc5c Mon Sep 17 00:00:00 2001
From: dan <dan@noemail.net>
Date: Thu, 10 Sep 2009 10:15:59 +0000
Subject: [PATCH] Remove an ALWAYS macro around an expression that is sometimes
 false.

FossilOrigin-Name: f2a9ee722c568e73f2a08fb6a2886719850f2923
---
 manifest         | 16 ++++++++--------
 manifest.uuid    |  2 +-
 src/select.c     | 26 ++++++++++++++++++--------
 test/capi3c.test | 34 ++++++++++++++++++++++++++++++++++
 4 files changed, 61 insertions(+), 17 deletions(-)

diff --git a/manifest b/manifest
index 5ea0016678..01a021a74f 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Reduce\sdefault\sSQLITE_MAX_TRIGGER_DEPTH\swhen\sSQLITE_SMALL_STACK\sis\sdefined.
-D 2009-09-10T02:54:49
+C Remove\san\sALWAYS\smacro\saround\san\sexpression\sthat\sis\ssometimes\sfalse.
+D 2009-09-10T10:15:59
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 73ddeec9dd10b85876c5c2ce1fdce627e1dcc7f8
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -159,7 +159,7 @@ F src/printf.c 508a1c59433353552b6553cba175eaa7331f8fc1
 F src/random.c 676b9d7ac820fe81e6fb2394ac8c10cff7f38628
 F src/resolve.c 941843301f6fda6c6350839c6955a172441a0782
 F src/rowset.c c64dafba1f9fd876836c8db8682966b9d197eb1f
-F src/select.c a7a075456d4e640ffd7d0a33202d306c69c88f72
+F src/select.c 1d0a13137532321b4364f964e46f057d271691e3
 F src/shell.c db2643650b9268df89a4bedca3f1c6d9e786f1bb
 F src/sqlite.h.in 5af8181f815831a8672c3834c60e6b4418448bcc
 F src/sqlite3ext.h 1db7d63ab5de4b3e6b83dd03d1a4e64fef6d2a17
@@ -266,7 +266,7 @@ F test/cache.test 3ff445c445742a7b6b9ba6e1d62a25263f9424b9
 F test/capi2.test 172c717ed101e78e0798dd21b9896a22366f35b4
 F test/capi3.test 168e2cd66c58c510955b0f299750e4de73b8d952
 F test/capi3b.test 664eb55318132f292f2c436f90906f578cad6b97
-F test/capi3c.test 946a95fc028c967aa6d9c8f6f527d1d3a748b68a
+F test/capi3c.test d9d293ce8fd4dc2944ce2dae5718fc7a6184a567
 F test/capi3d.test 57d83b690d7364bde02cddbf8339a4b50d80ce23
 F test/cast.test 166951664a0b0a2e0f8fb5997a152490c6363932
 F test/check.test b897cd3cc839b34b31cdd073e9882ccd03da977b
@@ -750,7 +750,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P ef99eb57c536d82e7c19fd3d990c17793cc64a3f
-R 767244a606af9968027fdbe6674a6b72
-U shane
-Z 2e97ef3fc800a5cf6d56a3a73bebbd68
+P 913fb70ea85f05d94db5cf2e692a7c8b7489e3ba
+R 0fa996f8c14954d9063c15cdbb2d4607
+U dan
+Z 5388363c4cc3ec0e91ee2d40bcc75a97
diff --git a/manifest.uuid b/manifest.uuid
index d37e771929..6a03c8c5ca 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-913fb70ea85f05d94db5cf2e692a7c8b7489e3ba
\ No newline at end of file
+f2a9ee722c568e73f2a08fb6a2886719850f2923
\ No newline at end of file
diff --git a/src/select.c b/src/select.c
index 21bc2be23c..f470befafe 100644
--- a/src/select.c
+++ b/src/select.c
@@ -884,7 +884,7 @@ static const char *columnType(
       int iCol = pExpr->iColumn;  /* Index of column in pTab */
       testcase( pExpr->op==TK_AGG_COLUMN );
       testcase( pExpr->op==TK_COLUMN );
-      while( ALWAYS(pNC) && !pTab ){
+      while( pNC && !pTab ){
         SrcList *pTabList = pNC->pSrcList;
         for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
         if( j<pTabList->nSrc ){
@@ -895,18 +895,28 @@ static const char *columnType(
         }
       }
 
-      if( NEVER(pTab==0) ){
+      if( pTab==0 ){
         /* At one time, code such as "SELECT new.x" within a trigger would
         ** cause this condition to run.  Since then, we have restructured how
         ** trigger code is generated and so this condition is no longer 
-        ** possible.  But it seems prudent to keep the test in place in
-        ** case something else changes.
-        */
-        zType = "TEXT";
+        ** possible. However, it can still be true for statements like
+        ** the following:
+        **
+        **   CREATE TABLE t1(col INTEGER);
+        **   SELECT (SELECT t1.col) FROM FROM t1;
+        **
+        ** when columnType() is called on the expression "t1.col" in the 
+        ** sub-select. In this case, set the column type to NULL, even
+        ** though it should really be "INTEGER".
+        **
+        ** This is not a problem, as the column type of "t1.col" is never
+        ** used. When columnType() is called on the expression 
+        ** "(SELECT t1.col)", the correct type is returned (see the TK_SELECT
+        ** branch below.  */
         break;
       }
 
-      assert( pTab );
+      assert( pTab && pExpr->pTab==pTab );
       if( pS ){
         /* The "table" is actually a sub-select or a view in the FROM clause
         ** of the SELECT statement. Return the declaration type and origin
@@ -920,7 +930,7 @@ static const char *columnType(
           NameContext sNC;
           Expr *p = pS->pEList->a[iCol].pExpr;
           sNC.pSrcList = pS->pSrc;
-          sNC.pNext = 0;
+          sNC.pNext = pNC;
           sNC.pParse = pNC->pParse;
           zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
         }
diff --git a/test/capi3c.test b/test/capi3c.test
index fd5eaeaa59..1bcc4373c2 100644
--- a/test/capi3c.test
+++ b/test/capi3c.test
@@ -1321,4 +1321,38 @@ ifcapable utf16 {
   sqlite3_finalize $STMT
 }
 
+# Test decltype on some SELECT statements that contain sub-selects.
+#
+proc decltype {zSql} {
+  set ret [list]
+  set STMT [sqlite3_prepare_v2 db $zSql -1 TAIL]
+  for {set i 0} {$i < [sqlite3_column_count $STMT]} {incr i} {
+    lappend ret [sqlite3_column_decltype $STMT $i]
+  }
+  sqlite3_finalize $STMT
+  return $ret
+}
+do_test capi3c-24.1 {
+  execsql { CREATE TABLE t5(a INTEGER, b STRING, c DATETIME) }
+  decltype {SELECT * FROM t5}
+} {INTEGER STRING DATETIME}
+do_test capi3c-24.2 {
+  decltype {SELECT (SELECT c) FROM t5}
+} {DATETIME}
+do_test capi3c-24.3 {
+  decltype {SELECT (SELECT * FROM (SELECT c)) FROM t5}
+} {DATETIME}
+do_test capi3c-24.4 {
+  decltype {SELECT * FROM (SELECT * FROM t5 ORDER BY c LIMIT 1) ORDER BY b}
+} {INTEGER STRING DATETIME}
+do_test capi3c-24.5 {
+  decltype {
+    SELECT (SELECT x FROM (SELECT c AS x)) 
+    FROM (SELECT * FROM t5 ORDER BY c LIMIT 1) ORDER BY b
+  }
+} {DATETIME}
+do_test capi3c-24.3 {
+  decltype {SELECT (SELECT x FROM (SELECT t5.a AS x)) FROM t5}
+} {INTEGER}
+
 finish_test