Add the SQLITE_LIMIT_TRIGGER_DEPTH option to sqlite3_limit().

FossilOrigin-Name: d7dc8b433691745b3842282569f1573d1e057963

src/main.c

@@ -1448,6 +1448,7 @@ static const int aHardLimit[] = {
   SQLITE_MAX_ATTACHED,
   SQLITE_MAX_LIKE_PATTERN_LENGTH,
   SQLITE_MAX_VARIABLE_NUMBER,
+  SQLITE_MAX_TRIGGER_DEPTH,
 };
 
 /*
@@ -1483,6 +1484,9 @@ static const int aHardLimit[] = {
 #if SQLITE_MAX_COLUMN>32767
 # error SQLITE_MAX_COLUMN must not exceed 32767
 #endif
+#if SQLITE_MAX_TRIGGER_DEPTH<1
+# error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
+#endif
 
 
 /*

src/select.c

@@ -881,7 +881,7 @@ 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( pNC && !pTab ){
+      while( ALWAYS(pNC) && !pTab ){
         SrcList *pTabList = pNC->pSrcList;
         for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
         if( j<pTabList->nSrc ){
@@ -892,16 +892,12 @@ static const char *columnType(
         }
       }
 
-      if( pTab==0 ){
-        /* FIX ME:
-        ** This can occurs if you have something like "SELECT new.x;" inside
-        ** a trigger.  In other words, if you reference the special "new"
-        ** table in the result set of a select.  We do not have a good way
-        ** to find the actual table type, so call it "TEXT".  This is really
-        ** something of a bug, but I do not know how to fix it.
-        **
-        ** This code does not produce the correct answer - it just prevents
-        ** a segfault.  See ticket #1229.
+      if( NEVER(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";
         break;

src/sqlite.h.in

@@ -2317,6 +2317,9 @@ int sqlite3_limit(sqlite3*, int id, int newVal);
 ** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
 ** <dd>The maximum number of variables in an SQL statement that can
 ** be bound.</dd>
+**
+** <dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
+** <dd>The maximum depth of recursion for triggers.</dd>
 ** </dl>
 */
 #define SQLITE_LIMIT_LENGTH                    0
@@ -2329,6 +2332,7 @@ int sqlite3_limit(sqlite3*, int id, int newVal);
 #define SQLITE_LIMIT_ATTACHED                  7
 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
 #define SQLITE_LIMIT_VARIABLE_NUMBER           9
+#define SQLITE_LIMIT_TRIGGER_DEPTH            10
 
 /*
 ** CAPI3REF: Compiling An SQL Statement {H13010} <S10000>

src/sqliteInt.h

@@ -707,7 +707,7 @@ struct Schema {
 ** The number of different kinds of things that can be limited
 ** using the sqlite3_limit() interface.
 */
-#define SQLITE_N_LIMIT (SQLITE_LIMIT_VARIABLE_NUMBER+1)
+#define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
 
 /*
 ** Lookaside malloc is a set of fixed-size buffers that can be used

src/sqliteLimit.h

@@ -188,3 +188,10 @@
 #ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
 # define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
 #endif
+
+/*
+** Maximum depth of recursion for triggers.
+*/
+#ifndef SQLITE_MAX_TRIGGER_DEPTH
+# define SQLITE_MAX_TRIGGER_DEPTH 1000
+#endif

src/test1.c

@@ -4721,10 +4721,11 @@ static int test_limit(
     { "SQLITE_LIMIT_ATTACHED",            SQLITE_LIMIT_ATTACHED             },
     { "SQLITE_LIMIT_LIKE_PATTERN_LENGTH", SQLITE_LIMIT_LIKE_PATTERN_LENGTH  },
     { "SQLITE_LIMIT_VARIABLE_NUMBER",     SQLITE_LIMIT_VARIABLE_NUMBER      },
+    { "SQLITE_LIMIT_TRIGGER_DEPTH",       SQLITE_LIMIT_TRIGGER_DEPTH        },
     
     /* Out of range test cases */
     { "SQLITE_LIMIT_TOOSMALL",            -1,                               },
-    { "SQLITE_LIMIT_TOOBIG",              SQLITE_LIMIT_VARIABLE_NUMBER+1    },
+    { "SQLITE_LIMIT_TOOBIG",              SQLITE_LIMIT_TRIGGER_DEPTH+1      },
   };
   int i, id;
   int val;

src/vdbe.c

@@ -4802,8 +4802,7 @@ case OP_Program: {        /* jump */
     if( pFrame ) break;
   }
 
-  /* TODO: This constant should be configurable. */
-  if( p->nFrame>1000 ){
+  if( p->nFrame>db->aLimit[SQLITE_LIMIT_TRIGGER_DEPTH] ){
     rc = SQLITE_ERROR;
     sqlite3SetString(&p->zErrMsg, db, "too many levels of trigger recursion");
     break;