Add verification of variable names in pgbench.

Variables must consist of only alphabets, numerals and underscores.
We had allowed to set variables with invalid names, but could not
refer them in queries.

Thanks to Robert Haas for the review.

contrib/pgbench/pgbench.c

@@ -4,7 +4,7 @@
  * A simple benchmark program for PostgreSQL
  * Originally written by Tatsuo Ishii and enhanced by many contributors.
  *
- * $PostgreSQL: pgsql/contrib/pgbench/pgbench.c,v 1.94 2010/01/02 16:57:32 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/pgbench/pgbench.c,v 1.95 2010/01/06 01:12:14 itagaki Exp $
  * Copyright (c) 2000-2010, PostgreSQL Global Development Group
  * ALL RIGHTS RESERVED;
  *
@@ -431,8 +431,23 @@ getVariable(CState *st, char *name)
 		return NULL;
 }
 
+/* check whether the name consists of alphabets, numerals and underscores. */
+static bool
+isLegalVariableName(const char *name)
+{
+	int		i;
+
+	for (i = 0; name[i] != '\0'; i++)
+	{
+		if (!isalnum((unsigned char) name[i]) && name[i] != '_')
+			return false;
+	}
+
+	return true;
+}
+
 static int
-putVariable(CState *st, char *name, char *value)
+putVariable(CState *st, const char *context, char *name, char *value)
 {
 	Variable	key,
 			   *var;
@@ -452,6 +467,16 @@ putVariable(CState *st, char *name, char *value)
 	{
 		Variable   *newvars;
 
+		/*
+		 * Check for the name only when declaring a new variable to avoid
+		 * overhead.
+		 */
+		if (!isLegalVariableName(name))
+		{
+			fprintf(stderr, "%s: invalid variable name '%s'\n", context, name);
+			return false;
+		}
+
 		if (st->variables)
 			newvars = (Variable *) realloc(st->variables,
 									(st->nvariables + 1) * sizeof(Variable));
@@ -459,7 +484,7 @@ putVariable(CState *st, char *name, char *value)
 			newvars = (Variable *) malloc(sizeof(Variable));
 
 		if (newvars == NULL)
-			return false;
+			goto out_of_memory;
 
 		st->variables = newvars;
 
@@ -493,6 +518,10 @@ putVariable(CState *st, char *name, char *value)
 	}
 
 	return true;
+
+out_of_memory:
+	fprintf(stderr, "%s: out of memory for variable '%s'\n", context, name);
+	return false;
 }
 
 static char *
@@ -687,11 +716,8 @@ runShellCommand(CState *st, char *variable, char **argv, int argc)
 		return false;
 	}
 	snprintf(res, sizeof(res), "%d", retval);
-	if (!putVariable(st, variable, res))
-	{
-		fprintf(stderr, "%s: out of memory\n", argv[0]);
+	if (!putVariable(st, "setshell", variable, res))
 		return false;
-	}
 
 #ifdef DEBUG
 	printf("shell parameter name: %s, value: %s\n", argv[1], res);
@@ -987,9 +1013,8 @@ top:
 #endif
 			snprintf(res, sizeof(res), "%d", getrand(min, max));
 
-			if (putVariable(st, argv[1], res) == false)
+			if (!putVariable(st, argv[0], argv[1], res))
 			{
-				fprintf(stderr, "%s: out of memory\n", argv[0]);
 				st->ecnt++;
 				return true;
 			}
@@ -1057,9 +1082,8 @@ top:
 				}
 			}
 
-			if (putVariable(st, argv[1], res) == false)
+			if (!putVariable(st, argv[0], argv[1], res))
 			{
-				fprintf(stderr, "%s: out of memory\n", argv[0]);
 				st->ecnt++;
 				return true;
 			}
@@ -1874,12 +1898,9 @@ main(int argc, char **argv)
 					}
 
 					*p++ = '\0';
-					if (putVariable(&state[0], optarg, p) == false)
-					{
-						fprintf(stderr, "Couldn't allocate memory for variable\n");
+					if (!putVariable(&state[0], "option", optarg, p))
 						exit(1);
 				}
-				}
 				break;
 			case 'F':
 				fillfactor = atoi(optarg);
@@ -1958,14 +1979,11 @@ main(int argc, char **argv)
 			state[i].id = i;
 			for (j = 0; j < state[0].nvariables; j++)
 			{
-				if (putVariable(&state[i], state[0].variables[j].name, state[0].variables[j].value) == false)
-				{
-					fprintf(stderr, "Couldn't allocate memory for variable\n");
+				if (!putVariable(&state[i], "startup", state[0].variables[j].name, state[0].variables[j].value))
 					exit(1);
 			}
 		}
 	}
-	}
 
 	if (use_log)
 	{
@@ -2039,13 +2057,10 @@ main(int argc, char **argv)
 		snprintf(val, sizeof(val), "%d", scale);
 		for (i = 0; i < nclients; i++)
 		{
-			if (putVariable(&state[i], "scale", val) == false)
-			{
-				fprintf(stderr, "Couldn't allocate memory for variable\n");
+			if (!putVariable(&state[i], "startup", "scale", val))
 				exit(1);
 		}
 	}
-	}
 
 	if (!is_no_vacuum)
 	{