From: Matthias Runge <mrunge@redhat.com>
Date: Tue, 7 Jan 2020 13:53:17 +0000 (+0100)
Subject: Merge pull request #3359 from Stackdriver/igorpeshansky-upstream-read_text_file_contents
X-Git-Url: https://git.octo.it/?a=commitdiff_plain;h=5ebc182261321f0781f38d8645bfc7c74353434c;hp=f7ba1418d1e2f18a53c19d28bb1be71f8f2b5c64;p=collectd.git

Merge pull request #3359 from Stackdriver/igorpeshansky-upstream-read_text_file_contents

Factor out read_text_file_contents to ensure that data read from text files is a valid C string.
---

diff --git a/src/aggregation.c b/src/aggregation.c
index 2c8ef880..e2f8ff1c 100644
--- a/src/aggregation.c
+++ b/src/aggregation.c
@@ -194,17 +194,21 @@ static int agg_instance_create_name(agg_instance_t *inst, /* {{{ */
       sstrncpy(tmp_plugin_instance, agg->ident.plugin_instance,
                sizeof(tmp_plugin_instance));
 
+    // Both tmp_plugin and tmp_plugin_instance are empty.
     if ((strcmp("", tmp_plugin) == 0) && (strcmp("", tmp_plugin_instance) == 0))
       sstrncpy(inst->ident.plugin_instance, AGG_FUNC_PLACEHOLDER,
                sizeof(inst->ident.plugin_instance));
-    else if (strcmp("", tmp_plugin) != 0)
+    // tmp_plugin is non-empty, and tmp_plugin_instance is empty.
+    else if (strcmp("", tmp_plugin_instance) == 0)
       ssnprintf(inst->ident.plugin_instance,
                 sizeof(inst->ident.plugin_instance), "%s-%s", tmp_plugin,
                 AGG_FUNC_PLACEHOLDER);
-    else if (strcmp("", tmp_plugin_instance) != 0)
+    // tmp_plugin is empty, and tmp_plugin_instance is non-empty.
+    else if (strcmp("", tmp_plugin) == 0)
       ssnprintf(inst->ident.plugin_instance,
                 sizeof(inst->ident.plugin_instance), "%s-%s",
                 tmp_plugin_instance, AGG_FUNC_PLACEHOLDER);
+    // Both tmp_plugin and tmp_plugin_instance are non-empty.
     else
       ssnprintf(inst->ident.plugin_instance,
                 sizeof(inst->ident.plugin_instance), "%s-%s-%s", tmp_plugin,