Add comment to explain why O_EXCL and O_TRUNC can be ignored in

openFlagsToCreateFileFlags() in certain cases.

diff --git a/src/port/open.c b/src/port/open.c
index a413176e3a9c1625a89d3098b9d4f328429f9cb0..f68b54cb6b3bb6634bdd9b14789874567c34b4d7 100644 (file)
--- a/src/port/open.c
+++ b/src/port/open.c
@@ -6,7 +6,7 @@
  *
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/port/open.c,v 1.18 2007/01/05 22:20:02 momjian Exp $
+ * $PostgreSQL: pgsql/src/port/open.c,v 1.19 2007/02/13 02:06:22 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -25,6 +25,7 @@ openFlagsToCreateFileFlags(int openFlags)
 {
    switch (openFlags & (O_CREAT | O_TRUNC | O_EXCL))
    {
+       /* O_EXCL is meaningless without O_CREAT */
        case 0:
        case O_EXCL:
            return OPEN_EXISTING;
@@ -32,6 +33,7 @@ openFlagsToCreateFileFlags(int openFlags)
        case O_CREAT:
            return OPEN_ALWAYS;
 
+       /* O_EXCL is meaningless without O_CREAT */
        case O_TRUNC:
        case O_TRUNC | O_EXCL:
            return TRUNCATE_EXISTING;
@@ -39,6 +41,7 @@ openFlagsToCreateFileFlags(int openFlags)
        case O_CREAT | O_TRUNC:
            return CREATE_ALWAYS;
 
+       /* O_TRUNC is meaningless with O_CREAT */
        case O_CREAT | O_EXCL:
        case O_CREAT | O_TRUNC | O_EXCL:
            return CREATE_NEW;