From 58e5fdc0ca76029c48f9523b4e4d7af4ae71abd2 Mon Sep 17 00:00:00 2001
From: Gilles Peskine <Gilles.Peskine@arm.com>
Date: Mon, 9 Oct 2017 16:54:28 +0200
Subject: [PATCH] config.pl get: don't rewrite config.h; detect write errors

scripts/config.pl would always rewrite config.h if it was reading it.
This commit changes it to not modify the file when only reading is
required, i.e. for the get command.

Also, die if writing config.h fails (e.g. disk full).
---
 scripts/config.pl | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/scripts/config.pl b/scripts/config.pl
index 4cf4ac8b8..9fc606278 100755
--- a/scripts/config.pl
+++ b/scripts/config.pl
@@ -175,7 +175,10 @@ if ($action eq "realfull") {
     $no_exclude_re = join '|', @non_excluded;
 }
 
-open my $config_write, '>', $config_file or die "write $config_file: $!\n";
+my $config_write = undef;
+if ($action ne "get") {
+    open $config_write, '>', $config_file or die "write $config_file: $!\n";
+}
 
 my $done;
 for my $line (@config_lines) {
@@ -211,7 +214,9 @@ for my $line (@config_lines) {
         }
     }
 
-    print $config_write $line;
+    if (defined $config_write) {
+        print $config_write $line or die "write $config_file: $!\n";;
+    }
 }
 
 # Did the set command work?
@@ -223,10 +228,12 @@ if ($action eq "set"&& $force_option && !$done) {
     $line .= "\n";
     $done = 1;
 
-    print $config_write $line;
+    print $config_write $line or die "write $config_file: $!\n";
 }
 
-close $config_write;
+if (defined $config_write) {
+    close $config_write or die "close $config_file: $!\n";
+}
 
 if ($action eq "get") {
     if($done) {