Merge pull request #318 from gportay/fix-invalid-cpu-placeholder

print_cpu_usage: fix invalid %cpu placeholder output

src/print_cpu_usage.c

@@ -151,7 +151,7 @@ void print_cpu_usage(yajl_gen json_gen, char *buffer, const char *format, const
         }
 #if defined(LINUX)
         else if (BEGINS_WITH(walk + 1, "cpu")) {
-            int number = 0;
+            int number = -1;
             sscanf(walk + 1, "cpu%d", &number);
             if (number < 0 || number >= cpu_count) {
                 fprintf(stderr, "provided CPU number '%d' above detected number of CPU %d\n", number, cpu_count);

testcases/024-cpu-usage-invalid-cpu/expected_output.pl

@@ -0,0 +1,7 @@
+#!/usr/bin/env perl
+
+use v5.10;
+use strict;
+use warnings;
+
+print "CPU: \n";

testcases/024-cpu-usage-invalid-cpu/i3status.conf

@@ -0,0 +1,9 @@
+general {
+        output_format = "none"
+}
+
+order += "cpu_usage"
+
+cpu_usage {
+    format = "CPU: %cpu"
+}