Always use the first attributes as fallback

This fixes parsing of data files generated with `perf record -s`.
In such a case, we do have non-empty attributes but the samples don't
reference any attribute by id. Perf uses the first available attribute
in such cases, cf. `perf_evlist__id2evsel`.

Change-Id: I1e5a9b59cd82dbe0d4eb1d140fb9b1e7768284fa
Reviewed-by: Milian Wolff <milian.wolff@kdab.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/app/perfunwind.cpp b/app/perfunwind.cpp
index 7a33f8f..9f8c1b4 100644
--- a/app/perfunwind.cpp
+++ b/app/perfunwind.cpp
@@ -236,12 +236,10 @@ void PerfUnwind::addAttributes(const PerfEventAttributes &attributes, const QByt
                               const QList<quint64> &ids)
 {
     auto filteredIds = ids;
-    if (filteredIds.isEmpty()) {
-        // If we only get one attribute, it doesn't have an ID.
-        // The default ID for samples is 0, so we assign that here,
-        // in order to look it up in analyze().
-        filteredIds = {0};
-    }
+    // If we only get one attribute, it doesn't have an ID.
+    // The default ID for samples is 0, so we assign that here,
+    // in order to look it up in analyze().
+    filteredIds << 0;
 
     {
         // remove attributes that are known already