Issue a warning whenever a double-quoted string literal is used.

FossilOrigin-Name: ac9ad5043026b30394812457e1535df2759aea0d4510029561e92e386672796f

manifest

@@ -1,5 +1,5 @@
-C Invoking\sthe\ssqlite3_trace()\sor\ssqlite3_trace_v2()\sinterfaces\scancels\nany\ssqlite3_profile()\sthat\sis\srunning.
-D 2018-12-06T03:59:25.918
+C Issue\sa\swarning\swhenever\sa\sdouble-quoted\sstring\sliteral\sis\sused.
+D 2018-12-06T16:11:14.066
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 68d0ba0f0b533d5bc84c78c13a6ce84ee81183a67014caa47a969e67f028fa1c
@@ -505,7 +505,7 @@ F src/pragma.h fdd03d78a7497f74a3f652909f945328480089189526841ae829ce7313d98d13
 F src/prepare.c 66b5f9791a3ef57131cbba58c33104ebea814a70a5cfcafabf5aed5a3e3858fe
 F src/printf.c 0f1177cf1dd4d7827bf64d840768514ec76409abecaca9e8b577dbd065150381
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
-F src/resolve.c 976e7879286a1eecdc71ceff64f6d1b3f58c8f8096537ba668b3dc0887f410c1
+F src/resolve.c e0408228bad5d13937a626521cba42c6f768643a6353712218d7e01fb201b202
 F src/rowset.c d977b011993aaea002cab3e0bb2ce50cf346000dff94e944d547b989f4b1fe93
 F src/select.c 61e867a906f140b73baf4ce7a201ad6dcba30820969f5618ee40e9a0d32c6f5f
 F src/shell.c.in 1f0819e69fb1ebd2eb44695530dc43936608bf9b752981a0ffd4e2e4a9e3883d
@@ -1782,7 +1782,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
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+R 3200e72b511607c15352eb3a60112ed6
 U drh
-Z 9b63335dca170db3a75ac781c84ad8b2
+Z 06f8f012c6fe6f33f55c7a711e9e6cc5

manifest.uuid

@@ -1 +1 @@
-ec63d3506bd429560077f82a4c5ed9d189780789fe1c134fff4f3b8733be1a3f
+ac9ad5043026b30394812457e1535df2759aea0d4510029561e92e386672796f

src/resolve.c

@@ -474,6 +474,22 @@ static int lookupName(
   if( cnt==0 && zTab==0 ){
     assert( pExpr->op==TK_ID );
     if( ExprHasProperty(pExpr,EP_DblQuoted) ){
+      /* If a double-quoted identifier does not match any known column name,
+      ** then treat it as a string.
+      **
+      ** This hack was added in the early days of SQLite in a misguided attempt
+      ** to be compatible with MySQL 3.x, which used double-quotes for strings.
+      ** I now sorely regret putting in this hack. The effect of this hack is
+      ** that misspelled identifier names are silently converted into strings
+      ** rather than causing an error, to the frustration of countless
+      ** programmers. To all those frustrated programmers, my apologies.
+      **
+      ** Someday, I hope to get rid of this hack. Unfortunately there is
+      ** a huge amount of legacy SQL that uses it. So for now, we just
+      ** issue a warning.
+      */
+      sqlite3_log(SQLITE_WARNING,
+        "double-quoted string literal: \"%w\"", zCol);
       pExpr->op = TK_STRING;
       pExpr->y.pTab = 0;
       return WRC_Prune;