NetBpfLoad: don't log the program failure buffer if it is empty am: 9f8b17ee5b

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3250532

Change-Id: I0557d66d34267694d97d418d2b7b68bc9809b31b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/bpf/loader/NetBpfLoad.cpp b/bpf/loader/NetBpfLoad.cpp
index 93dffb6..2267fab 100644
--- a/bpf/loader/NetBpfLoad.cpp
+++ b/bpf/loader/NetBpfLoad.cpp
@@ -1011,11 +1011,13 @@
                   cs[i].name.c_str(), fd.get(), (!fd.ok() ? std::strerror(errno) : "no error"));
 
             if (!fd.ok()) {
-                vector<string> lines = android::base::Split(log_buf.data(), "\n");
+                if (log_buf.size()) {
+                    vector<string> lines = android::base::Split(log_buf.data(), "\n");
 
-                ALOGW("BPF_PROG_LOAD - BEGIN log_buf contents:");
-                for (const auto& line : lines) ALOGW("%s", line.c_str());
-                ALOGW("BPF_PROG_LOAD - END log_buf contents.");
+                    ALOGW("BPF_PROG_LOAD - BEGIN log_buf contents:");
+                    for (const auto& line : lines) ALOGW("%s", line.c_str());
+                    ALOGW("BPF_PROG_LOAD - END log_buf contents.");
+                }
 
                 if (cs[i].prog_def->optional) {
                     ALOGW("failed program %s is marked optional - continuing...",