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

bmomjian · bmomjian · commit 849b0707079e · 2007-02-13T02:06:22.000Z
openFlagsToCreateFileFlags() in certain cases.
diff --git 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 $
  *
  *-------------------------------------------------------------------------
  */
@@ -25,20 +25,23 @@ 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;
 
 		case O_CREAT:
 			return OPEN_ALWAYS;
 
+		/* O_EXCL is meaningless without O_CREAT */
 		case O_TRUNC:
 		case O_TRUNC | O_EXCL:
 			return TRUNCATE_EXISTING;
 
 		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;

Original file line number	Diff line number	Diff line change
`@@ -6,7 +6,7 @@`
`6`	`6`	`*`
`7`	`7`	`* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group`
`8`	`8`	`*`
`9`		`- * $PostgreSQL: pgsql/src/port/open.c,v 1.18 2007/01/05 22:20:02 momjian Exp $`
	`9`	`+ * $PostgreSQL: pgsql/src/port/open.c,v 1.19 2007/02/13 02:06:22 momjian Exp $`
`10`	`10`	`*`
`11`	`11`	`*-------------------------------------------------------------------------`
`12`	`12`	`*/`
`@@ -25,20 +25,23 @@ openFlagsToCreateFileFlags(int openFlags)`
`25`	`25`	`{`
`26`	`26`	`switch (openFlags & (O_CREAT \| O_TRUNC \| O_EXCL))`
`27`	`27`	`{`
	`28`	`+ /* O_EXCL is meaningless without O_CREAT */`
`28`	`29`	`case 0:`
`29`	`30`	`case O_EXCL:`
`30`	`31`	`return OPEN_EXISTING;`
`31`	`32`
`32`	`33`	`case O_CREAT:`
`33`	`34`	`return OPEN_ALWAYS;`
`34`	`35`
	`36`	`+ /* O_EXCL is meaningless without O_CREAT */`
`35`	`37`	`case O_TRUNC:`
`36`	`38`	`case O_TRUNC \| O_EXCL:`
`37`	`39`	`return TRUNCATE_EXISTING;`
`38`	`40`
`39`	`41`	`case O_CREAT \| O_TRUNC:`
`40`	`42`	`return CREATE_ALWAYS;`
`41`	`43`
	`44`	`+ /* O_TRUNC is meaningless with O_CREAT */`
`42`	`45`	`case O_CREAT \| O_EXCL:`
`43`	`46`	`case O_CREAT \| O_TRUNC \| O_EXCL:`
`44`	`47`	`return CREATE_NEW;`