wslog: Fix initialization with invalid environment

We can't write to stderr outside of the default writer context.
Wireshark and tshark will block if we do that and dumpcap is
running as capture child.

1 files changed, 11 insertions, 6 deletions

diff --git a/wsutil/wslog.c b/wsutil/wslog.c
index 53d8fd8f63..3f505db7c4 100644
--- a/wsutil/wslog.c
+++ b/wsutil/wslog.c
@@ -526,6 +526,11 @@ enum ws_log_level ws_log_set_fatal_str(const char *str_level)
 }
 
 
+/*
+ * We can't write to stderr in ws_log_init() because dumpcap uses stderr
+ * to communicate with the parent and it will block. Any failures are
+ * therefore ignored.
+ */
 void ws_log_init(const char *progname, ws_log_writer_cb *writer)
 {
     const char *env;
@@ -552,17 +557,17 @@ void ws_log_init(const char *progname, ws_log_writer_cb *writer)
     current_log_level = DEFAULT_LOG_LEVEL;
 
     env = g_getenv(ENV_VAR_LEVEL);
-    if (env != NULL && ws_log_set_level_str(env) == LOG_LEVEL_NONE)
-        fprintf(stderr, "Ignoring invalid environment value %s=\"%s\".\n", ENV_VAR_LEVEL, env);
+    if (env != NULL)
+        ws_log_set_level_str(env);
+
+    env = g_getenv(ENV_VAR_FATAL);
+    if (env != NULL)
+        ws_log_set_fatal_str(env);
 
     env = g_getenv(ENV_VAR_DOMAINS);
     if (env != NULL)
         ws_log_set_domain_filter(env);
 
-    env = g_getenv(ENV_VAR_FATAL);
-    if (env != NULL && ws_log_set_fatal_str(env) == LOG_LEVEL_NONE)
-        fprintf(stderr, "Ignoring invalid environment value %s=\"%s\".\n", ENV_VAR_FATAL, env);
-
     env = g_getenv(ENV_VAR_DEBUG);
     if (env != NULL)
         ws_log_set_debug_filter(env);