[BUGS] phantom row from empty table

[pacman]

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                        POSTGRESQL BUG REPORT TEMPLATE
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Your name               :       Alan Curry
Your email address      :       [EMAIL PROTECTED]


System Configuration
---------------------
  Architecture (example: Intel Pentium)         :Pentium Pro

  Operating System (example: Linux 2.0.26 ELF)  :Linux 2.2.13 ELF

  PostgreSQL version (example: PostgreSQL-6.5.2):PostgreSQL-6.5.3

  Compiler used (example:  gcc 2.8.0)           :gcc 2.7.2.3


Please enter a FULL description of your problem:
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It is possible to select a phantom row from an empty table.




Please describe a way to repeat the problem.   Please try to provide a
concise reproducible example, if at all possible: 
----------------------------------------------------------------------
test=> create table foo(u text, i int);
CREATE
test=> select * from foo;
u|i
-+-
(0 rows)

test=> select u,min(i) from foo group by u;
u|min
-+---
 |
(1 row)


#include <libpq-fe.h>
#include <stdio.h>

int main(void)
{
  PGconn *db;
  PGresult *res;
  int r, c, i;

  db=PQconnectdb("dbname=test");
  if(PQstatus(db)!=CONNECTION_OK) {
    fprintf(stderr, "PQconnectdb: %s", PQerrorMessage(db));
    return 1;
  }

  res=PQexec(db, "drop table foo;");
  if(PQresultStatus(res)!=PGRES_COMMAND_OK) {
    fprintf(stderr, "died at %d %s", __LINE__, PQresultErrorMessage(res));
    return 1;
  }

  res=PQexec(db, "create table foo(u text, i int);");
  if(PQresultStatus(res)!=PGRES_COMMAND_OK) {
    fprintf(stderr, "died at %d %s", __LINE__, PQresultErrorMessage(res));
    return 1;
  }

  /* Hey Rocky, watch me pull a rabbit out of my hat! */
  res=PQexec(db, "select u, min(i) from foo group by u;");
  if(PQresultStatus(res)!=PGRES_TUPLES_OK) {
    fprintf(stderr, "died at %d %s", __LINE__, PQresultErrorMessage(res));
    return 1;
  }
  r=PQntuples(res);
  if(!r)
    return 0;
  printf("Got %d row%s from a table with no rows in it!\n", r, r>1?"s":"");
  c=PQnfields(res);
  printf("Dumping row 0\n");
  for(i=0;i<c;++i) {
    printf("column %d (%s) is %snull, with value \"%s\"\n", i,
           PQfname(res, i),
           PQgetisnull(res, 0, i)?"":"not ",
           PQgetvalue(res, 0, i));
  }
  return 0;
}



If you know how this problem might be fixed, list the solution below:
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