Remove pgbench's hardwired limit on line length in custom script files.

pgbench formerly failed on lines longer than BUFSIZ, unexpectedly
splitting them into multiple commands.  Allow it to work with any
length of input line.

Sawada Masahiko

contrib/pgbench/pgbench.c

@@ -2016,6 +2016,49 @@ process_commands(char *buf)
 	return my_commands;
 }
 
+/*
+ * Read a line from fd, and return it in a malloc'd buffer.
+ * Return NULL at EOF.
+ *
+ * The buffer will typically be larger than necessary, but we don't care
+ * in this program, because we'll free it as soon as we've parsed the line.
+ */
+static char *
+read_line_from_file(FILE *fd)
+{
+	char		tmpbuf[BUFSIZ];
+	char	   *buf;
+	size_t		buflen = BUFSIZ;
+	size_t		used = 0;
+
+	buf = (char *) palloc(buflen);
+	buf[0] = '\0';
+
+	while (fgets(tmpbuf, BUFSIZ, fd) != NULL)
+	{
+		size_t		thislen = strlen(tmpbuf);
+
+		/* Append tmpbuf to whatever we had already */
+		memcpy(buf + used, tmpbuf, thislen + 1);
+		used += thislen;
+
+		/* Done if we collected a newline */
+		if (thislen > 0 && tmpbuf[thislen - 1] == '\n')
+			break;
+
+		/* Else, enlarge buf to ensure we can append next bufferload */
+		buflen += BUFSIZ;
+		buf = (char *) pg_realloc(buf, buflen);
+	}
+
+	if (used > 0)
+		return buf;
+
+	/* Reached EOF */
+	free(buf);
+	return NULL;
+}
+
 static int
 process_file(char *filename)
 {
@@ -2024,7 +2067,7 @@ process_file(char *filename)
 	Command   **my_commands;
 	FILE	   *fd;
 	int			lineno;
-	char		buf[BUFSIZ];
+	char	   *buf;
 	int			alloc_num;
 
 	if (num_files >= MAX_FILES)
@@ -2046,11 +2089,14 @@ process_file(char *filename)
 
 	lineno = 0;
 
-	while (fgets(buf, sizeof(buf), fd) != NULL)
+	while ((buf = read_line_from_file(fd)) != NULL)
 	{
 		Command    *command;
 
 		command = process_commands(buf);
+
+		free(buf);
+
 		if (command == NULL)
 			continue;