Use the subquery column name, not the original SQL statement text, as the

added AS clause in the query flattener.

FossilOrigin-Name: 5df7f0e6a1fbc770a68830ce88e78ecccbf023557ea446ce312ab53d5b32a6a9

manifest

@@ -1,5 +1,5 @@
-C Update\sTcl\sversion\sused\sby\sthe\sTclKit\sbatch\stool\sfor\sMSVC.
-D 2017-07-28T22:22:15.250
+C Use\sthe\ssubquery\scolumn\sname,\snot\sthe\soriginal\sSQL\sstatement\stext,\sas\sthe\nadded\sAS\sclause\sin\sthe\squery\sflattener.
+D 2017-07-29T14:56:53.996
 F Makefile.in d9873c9925917cca9990ee24be17eb9613a668012c85a343aef7e5536ae266e8
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 02b469e9dcd5b7ee63fc1fb05babc174260ee4cfa4e0ef2e48c3c6801567a016
@@ -452,7 +452,7 @@ F src/printf.c 8757834f1b54dae512fb25eb1acc8e94a0d15dd2290b58f2563f65973265adb2
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 4324a94573b1e29286f8121e4881db59eaedc014afeb274c8d3e07ed282e0e20
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
-F src/select.c c6bf96a7f9d7d68f929de84738c599a30d0a725ab0b54420e70545743cd5ee7b
+F src/select.c ef0be59b8394507c139678a8b6f1c9e8ea028b12200b5e38bc0992560341a035
 F src/shell.c bd6a37cbe8bf64ef6a6a74fdc50f067d3148149b4ce2b4d03154663e66ded55f
 F src/shell.c.in b5725acacba95ccefa57b6d068f710e29ba8239c3aa704628a1902a1f729c175
 F src/sqlite.h.in 0e2603c23f0747c5660669f946e231730af000c76d1653b153dcf2c26fce0a6b
@@ -1637,7 +1637,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 3286e1a07b0693049a07f0865bf93749c461ea8f6d1175ec2d1642886673d8ac
-R fa880debd22b5643c43c3f5ac12562f1
-U mistachkin
-Z 2ba3113508e5372bd91f947e270302b1
+P 439cc5c52cbe6e67bbf0b6de0610f7d95ca9eb994f032547dc3535fd2c9dfc78
+R 958b536ad819a7cfdc8789f87ebdcbab
+U drh
+Z 4ab6903a815161b50ba952b68c66e144

manifest.uuid

@@ -1 +1 @@
-bcec155e0d6c6b17ae09d5a366c080723d01ff40dbc1a0ad0bb669a91db1b850
+5df7f0e6a1fbc770a68830ce88e78ecccbf023557ea446ce312ab53d5b32a6a9

src/select.c

@@ -3769,7 +3769,46 @@ static int flattenSubquery(
       memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
     }
     pSrc->a[iFrom].fg.jointype = jointype;
-  
+
+    /* For every result column in the outer query that does not have an AS
+    ** clause, if that column is a reference to an output column from the
+    ** inner query, then preserve the name of the column by adding an AS clause.
+    ** This prevents the outer query column from taking on a name derived
+    ** from inner query column name.
+    **
+    ** Example:
+    **     CREATE TABLE t1(a,b);
+    **     CREATE VIEW v1(x,y) AS SELECT a,b FROM t1;
+    **     SELECT x,y FROM v1;
+    **
+    ** The inner "v1" subquery will get flattened into the outer query.  After
+    ** flattening, the outer query becomes:  "SELECT a,b FROM t1".  But the
+    ** new query gives column names of "a" and "b", not the "x" and "y" that
+    ** the programmer expected.  This step adds AS clauses so that the
+    ** flattened query becomes:  "SELECT a AS x, b AS y FROM t1".
+    **
+    ** Update on 2017-07-29:  The current implementation only adds AS clauses
+    ** to outer query result columns that are substituted directly for
+    ** columns of the inner query.  Formerly, all result columns in the outer
+    ** query got new AS clauses if they didn't have them all ready.  Also,
+    ** the name of the AS clause is taken from the result column name of
+    ** the inner query.  Formerly, the name was a copy of the text of the
+    ** original SQL statement that specified the column.
+    */
+    pList = pParent->pEList;
+    for(i=0; i<pList->nExpr; i++){
+      Expr *p;
+      if( pList->a[i].zName==0
+       && (p = pList->a[i].pExpr)->op==TK_COLUMN
+       && p->iTable==iParent
+       && p->iColumn>=0
+       && ALWAYS(p->pTab!=0)
+      ){
+        char *zName = sqlite3DbStrDup(db, p->pTab->aCol[p->iColumn].zName);
+        pList->a[i].zName = zName;
+      }
+    }
+
     /* Now begin substituting subquery result set expressions for 
     ** references to the iParent in the outer query.
     ** 
@@ -3782,14 +3821,6 @@ static int flattenSubquery(
     ** We look at every expression in the outer query and every place we see
     ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
     */
-    pList = pParent->pEList;
-    for(i=0; i<pList->nExpr; i++){
-      if( pList->a[i].zName==0 ){
-        char *zName = sqlite3DbStrDup(db, pList->a[i].zSpan);
-        sqlite3Dequote(zName);
-        pList->a[i].zName = zName;
-      }
-    }
     if( pSub->pOrderBy ){
       /* At this point, any non-zero iOrderByCol values indicate that the
       ** ORDER BY column expression is identical to the iOrderByCol'th