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Check-in [d537aa5ede]
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Overview
Comment:Additional memory initialization in lemon - bug reported from wireshark. Ticket #2172. Note this problem only comes up with certain grammars, and does not impact SQLite. On the other hand, it might cause SQLite to run slower. So we might want to revisit this change at some point. (CVS 3594)
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SHA1: d537aa5edecb5c7b84d8eb876453f385f6f3d91a
User & Date: drh 2007-01-16 18:19:13.000
Context
2007-01-19
01:06
Make sure the IS NULL optimization introduced by check-in (3494) correctly handles a LEFT JOIN where the a term from the right table of the join uses an IS NULL constraint. Ticket #2177. This check-in also adds the new test cases that were suppose to have been added with (3494) but which were mistakenly omitted. (CVS 3595) (check-in: 335863e4d1 user: drh tags: trunk)
2007-01-16
18:19
Additional memory initialization in lemon - bug reported from wireshark. Ticket #2172. Note this problem only comes up with certain grammars, and does not impact SQLite. On the other hand, it might cause SQLite to run slower. So we might want to revisit this change at some point. (CVS 3594) (check-in: d537aa5ede user: drh tags: trunk)
03:09
Make sure the parser generated by lemon always calls destructors on unused symbols, even if there is no action following the rule. Ticket #2171. (CVS 3593) (check-in: 0c5c1b931d user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to tool/lempar.c.
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  if( yyTraceFILE && yyruleno>=0 
        && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
    fprintf(yyTraceFILE, "%sReduce [%s].\n", yyTracePrompt,
      yyRuleName[yyruleno]);
  }
#endif /* NDEBUG */

#ifndef NDEBUG
  /* Silence complaints from purify about yygotominor being uninitialized
  ** in some cases when it is copied into the stack after the following
  ** switch.  yygotominor is uninitialized when a rule reduces that does
  ** not set the value of its left-hand side nonterminal.  Leaving the
  ** value of the nonterminal uninitialized is utterly harmless as long
  ** as the value is never used.  So really the only thing this code
  ** accomplishes is to quieten purify.  






  */
  memset(&yygotominor, 0, sizeof(yygotominor));
#endif

  switch( yyruleno ){
  /* Beginning here are the reduction cases.  A typical example
  ** follows:
  **   case 0:
  **  #line <lineno> <grammarfile>
  **     { ... }           // User supplied code








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  if( yyTraceFILE && yyruleno>=0 
        && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
    fprintf(yyTraceFILE, "%sReduce [%s].\n", yyTracePrompt,
      yyRuleName[yyruleno]);
  }
#endif /* NDEBUG */


  /* Silence complaints from purify about yygotominor being uninitialized
  ** in some cases when it is copied into the stack after the following
  ** switch.  yygotominor is uninitialized when a rule reduces that does
  ** not set the value of its left-hand side nonterminal.  Leaving the
  ** value of the nonterminal uninitialized is utterly harmless as long
  ** as the value is never used.  So really the only thing this code
  ** accomplishes is to quieten purify.  
  **
  ** 2007-01-16:  The wireshark project (www.wireshark.org) reports that
  ** without this code, their parser segfaults.  I'm not sure what there
  ** parser is doing to make this happen.  This is the second bug report
  ** from wireshark this week.  Clearly they are stressing Lemon in ways
  ** that it has not been previously stressed...  (SQLite ticket #2172)
  */
  memset(&yygotominor, 0, sizeof(yygotominor));


  switch( yyruleno ){
  /* Beginning here are the reduction cases.  A typical example
  ** follows:
  **   case 0:
  **  #line <lineno> <grammarfile>
  **     { ... }           // User supplied code
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