Windows: Work around an oddity when a pipe with no reader is written to.

Johannes Sixt · Johannes Sixt · commit b2f5e2684da0 · 2008-06-26T08:47:15.000+02:00
On Windows, write() is implemented using WriteFile(). After the reader
closed its end of the pipe, the first WriteFile() returns
ERROR_BROKEN_PIPE (which translates to EPIPE), subsequent WriteFile()s
return ERROR_NO_DATA, which is translated to EINVAL.

Signed-off-by: Johannes Sixt &lt;johannes.sixt@telecom.at&gt;
diff --git a/write_or_die.c b/write_or_die.c
@@ -34,7 +34,12 @@ void maybe_flush_or_die(FILE *f, const char *desc)
 			return;
 	}
 	if (fflush(f)) {
-		if (errno == EPIPE)
+		/*
+		 * On Windows, EPIPE is returned only by the first write()
+		 * after the reading end has closed its handle; subsequent
+		 * write()s return EINVAL.
+		 */
+		if (errno == EPIPE || errno == EINVAL)
 			exit(0);
 		die("write failure on %s: %s", desc, strerror(errno));
 	}

Original file line number	Diff line number	Diff line change
`@@ -34,7 +34,12 @@ void maybe_flush_or_die(FILE f, const char desc)`
`34`	`34`	`return;`
`35`	`35`	`}`
`36`	`36`	`if (fflush(f)) {`
`37`		`- if (errno == EPIPE)`
	`37`	`+ /*`
	`38`	`+ * On Windows, EPIPE is returned only by the first write()`
	`39`	`+ * after the reading end has closed its handle; subsequent`
	`40`	`+ * write()s return EINVAL.`
	`41`	`+ */`
	`42`	`+ if (errno == EPIPE \|\| errno == EINVAL)`
`38`	`43`	`exit(0);`
`39`	`44`	`die("write failure on %s: %s", desc, strerror(errno));`
`40`	`45`	`}`