From: Bob Moore <robert.moore@intel.com>
Date: Wed, 14 Mar 2018 16:13:02 -0700
Subject: ACPICA: AML Debug Object: Don't ignore output of zero-length strings
Patch-mainline: v4.17-rc1
Git-commit: 816772412101bd41fdab01aa7ce575b3a6392cd4
References: bsc#1117419

The implementation previously ignored null strings (""), but
these could be important, especially for debug.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/acpi/acpica/exdebug.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--- a/drivers/acpi/acpica/exdebug.c
+++ b/drivers/acpi/acpica/exdebug.c
@@ -88,14 +88,13 @@ acpi_ex_do_debug_object(union acpi_opera
 		return_VOID;
 	}
 
-	/* Null string or newline -- don't emit the line header */
+	/* Newline -- don't emit the line header */
 
 	if (source_desc &&
 	    (ACPI_GET_DESCRIPTOR_TYPE(source_desc) == ACPI_DESC_TYPE_OPERAND) &&
 	    (source_desc->common.type == ACPI_TYPE_STRING)) {
-		if ((source_desc->string.length == 0) ||
-		    ((source_desc->string.length == 1) &&
-		     (*source_desc->string.pointer == '\n'))) {
+		if ((source_desc->string.length == 1) &&
+		    (*source_desc->string.pointer == '\n')) {
 			acpi_os_printf("\n");
 			return_VOID;
 		}