From: Alex Bennée <alex.bennee@linaro.org>
Date: Tue, 25 Feb 2020 12:47:00 +0000 (+0000)
Subject: tracing: only allow -trace to override -D if set
X-Git-Tag: v5.0.0-rc0~73^2~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3d88754e2b096ace0f9c2e86dbbb84de4290d421;p=thirdparty%2Fqemu.git

tracing: only allow -trace to override -D if set

Otherwise any -D settings the user may have made get ignored.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Robert Foley <robert.foley@linaro.org>
Message-Id: <20200225124710.14152-10-alex.bennee@linaro.org>
---

diff --git a/trace/control.c b/trace/control.c
index 6c775e68eba..2ffe0008184 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -226,10 +226,15 @@ void trace_init_file(const char *file)
 #ifdef CONFIG_TRACE_SIMPLE
     st_set_trace_file(file);
 #elif defined CONFIG_TRACE_LOG
-    /* If both the simple and the log backends are enabled, "--trace file"
-     * only applies to the simple backend; use "-D" for the log backend.
+    /*
+     * If both the simple and the log backends are enabled, "--trace file"
+     * only applies to the simple backend; use "-D" for the log
+     * backend. However we should only override -D if we actually have
+     * something to override it with.
      */
-    qemu_set_log_filename(file, &error_fatal);
+    if (file) {
+        qemu_set_log_filename(file, &error_fatal);
+    }
 #else
     if (file) {
         fprintf(stderr, "error: --trace file=...: "