[PATCH] kbuild: Add error handling to KCONFIG_ALL_CONFIG

[ebiederm@xmission.com (Eric W. Biederman)]

- Only try to read the file specified if KCONFIG_ALL_CONFIG is set to
  something other than the empty string.

- Don't use stat to check the name passed to conf_read_simple so that
  zconf_fopen can find the file in the current directory or in SRCTREE
  removing a extremely confusing failure mode, where KCONFIG_ALL_CONFIG
  was not interpreted with respect to the directory make was called in.

- If conf_read_simple fails complain clearly and stop processing.
  Allowing the simple discovery and debugging of command line typos.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 scripts/kconfig/conf.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 28910ea..af6a2db 100644
--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -579,8 +579,13 @@ int main(int ac, char **av)
 	case alldefconfig:
 	case randconfig:
 		name = getenv("KCONFIG_ALLCONFIG");
-		if (name && !stat(name, &tmpstat)) {
-			conf_read_simple(name, S_DEF_USER);
+		if (name && name[0] != '\0') {
+			if (conf_read_simple(name, S_DEF_USER)) {
+				fprintf(stderr,
+					_("*** Can't read seed configuration \"%s\"!\n"),
+					name);
+				exit(1);
+			}
 			break;
 		}
 		switch (input_mode) {
-- 
1.7.2.5