MXS-1719 Treat # comments the same way as -- comments

sqlite does not treat # as the start of a to-end-of-line
comment. It cannot trivially be treated as such because at
startup sqlite parses statements containing the #-character.
Thus, only after sqlite has been initialized can it be treated
the same way as --.

query_classifier/qc_sqlite/qc_sqlite.cc

@@ -2110,15 +2110,25 @@ public:
         update_names(zDatabase, table, NULL, NULL);
     }
 
-    void maxscaleComment()
+    int maxscaleComment()
     {
-        ss_dassert(this_thread.initialized);
+        // We are regularily parsing if the thread has been initialized.
+        // In that case # should be interpreted as the start of a comment,
+        // otherwise it should not.
+        int regular_parsing = false;
 
-        if (m_status == QC_QUERY_INVALID)
+        if (this_thread.initialized)
         {
-            m_status = QC_QUERY_PARSED;
+            regular_parsing = true;
-            m_type_mask = QUERY_TYPE_READ;
+
+            if (m_status == QC_QUERY_INVALID)
+            {
+                m_status = QC_QUERY_PARSED;
+                m_type_mask = QUERY_TYPE_READ;
+            }
         }
+
+        return regular_parsing;
     }
 
     void maxscaleDeclare(Parse* pParse)

query_classifier/qc_sqlite/sqlite-src-3110100/src/tokenize.c

@@ -198,6 +198,7 @@ int sqlite3IsIdChar(u8 c){ return IdChar(c); }
 ** Store the token type in *tokenType before returning.
 */
 #ifdef MAXSCALE
+extern int maxscaleComment();
 int sqlite3GetToken(Parse* pParse, const unsigned char *z, int *tokenType){
 #else
 int sqlite3GetToken(const unsigned char *z, int *tokenType){
@@ -219,8 +220,7 @@ int sqlite3GetToken(const unsigned char *z, int *tokenType){
     case CC_MINUS: {
       if( z[1]=='-' ){
 #ifdef MAXSCALE
-          extern void maxscaleComment();
+        maxscaleComment();
-          maxscaleComment();
 #endif
         for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
         *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
@@ -466,6 +466,13 @@ int sqlite3GetToken(const unsigned char *z, int *tokenType){
       testcase( z[0]=='$' );  testcase( z[0]=='@' );
       testcase( z[0]==':' );  testcase( z[0]=='#' );
 #ifdef MAXSCALE
+      if (z[0]=='#') {
+        if (maxscaleComment()) {
+          for(i=1; (c=z[i])!=0 && c!='\n'; i++){}
+          *tokenType = TK_SPACE;
+          return i;
+        }
+      }
       if (z[0]==':' && z[1]=='=') {
         *tokenType = TK_EQ;
         return 2;