Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -401,11 +401,11 @@
       sqlite3DbFree(db, pOld);
     }
     pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
   }
   pTerm = &pWC->a[idx = pWC->nTerm++];
-  pTerm->pExpr = p;
+  pTerm->pExpr = sqlite3ExprSkipCollate(p);
   pTerm->wtFlags = wtFlags;
   pTerm->pWC = pWC;
   pTerm->iParent = -1;
   return idx;
 }
@@ -1186,11 +1186,12 @@
   if( db->mallocFailed ){
     return;
   }
   pTerm = &pWC->a[idxTerm];
   pMaskSet = pWC->pMaskSet;
-  pExpr = sqlite3ExprSkipCollate(pTerm->pExpr);
+  pExpr = pTerm->pExpr;
+  assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
   prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
   op = pExpr->op;
   if( op==TK_IN ){
     assert( pExpr->pRight==0 );
     if( ExprHasProperty(pExpr, EP_xIsSelect) ){

ADDED   test/tkt-a7b7803e.test
Index: test/tkt-a7b7803e.test
==================================================================
--- /dev/null
+++ test/tkt-a7b7803e.test
@@ -0,0 +1,84 @@
+# 2012 December 19
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library. Specifically,
+# it tests that ticket [a7b7803e8d1e8699cd8a460a38133b98892d2e17] has
+# been fixed.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+
+do_test tkt-a7b7803e.1 {
+  db eval {
+    CREATE TABLE t1(a,b);
+    INSERT INTO t1 VALUES(0,'first'),(99,'fuzzy');
+    SELECT (t1.a==0) AS x, b
+      FROM t1
+     WHERE a=0 OR x;
+  }
+} {1 first}
+do_test tkt-a7b7803e.2 {
+  db eval {
+    SELECT a, (t1.b='fuzzy') AS x
+      FROM t1
+     WHERE x
+  }
+} {99 1}
+do_test tkt-a7b7803e.3 {
+  db eval {
+    SELECT (a=99) AS x, (t1.b='fuzzy') AS y, *
+      FROM t1
+     WHERE x AND y
+  }
+} {1 1 99 fuzzy}
+do_test tkt-a7b7803e.4 {
+  db eval {
+    SELECT (a=99) AS x, (t1.b='first') AS y, *
+      FROM t1
+     WHERE x OR y
+     ORDER BY a
+  }
+} {0 1 0 first 1 0 99 fuzzy}
+do_test tkt-a7b7803e.5 {
+  db eval {
+    SELECT (M.a=99) AS x, M.b, (N.b='first') AS y, N.b
+      FROM t1 M, t1 N
+     WHERE x OR y
+     ORDER BY M.a, N.a
+  }
+} {0 first 1 first 1 fuzzy 1 first 1 fuzzy 0 fuzzy}
+do_test tkt-a7b7803e.6 {
+  db eval {
+    SELECT (M.a=99) AS x, M.b, (N.b='first') AS y, N.b
+      FROM t1 M, t1 N
+     WHERE x AND y
+     ORDER BY M.a, N.a
+  }
+} {1 fuzzy 1 first}
+do_test tkt-a7b7803e.7 {
+  db eval {
+    SELECT (M.a=99) AS x, M.b, (N.b='first') AS y, N.b
+      FROM t1 M JOIN t1 N ON x AND y
+     ORDER BY M.a, N.a
+  }
+} {1 fuzzy 1 first}
+do_test tkt-a7b7803e.8 {
+  db eval {
+    SELECT (M.a=99) AS x, M.b, (N.b='first') AS y, N.b
+      FROM t1 M JOIN t1 N ON x
+     ORDER BY M.a, N.a
+  }
+} {1 fuzzy 1 first 1 fuzzy 0 fuzzy}
+
+
+finish_test