diff --git a/libsoup/soup-auth-basic.c b/libsoup/soup-auth-basic.c
index 5f1e718..d8b3226 100644
--- a/libsoup/soup-auth-basic.c
+++ b/libsoup/soup-auth-basic.c
@@ -74,7 +74,7 @@ soup_auth_basic_get_protection_space (SoupAuth *auth, SoupURI *source_uri)
 
 	/* Strip filename component */
 	p = strrchr (space, '/');
-	if (p == space && p[1])
+	if (p && p == space && p[1])
 		p[1] = '\0';
 	else if (p && p[1])
 		*p = '\0';
diff --git a/libsoup/soup-auth-negotiate.c b/libsoup/soup-auth-negotiate.c
index 94863d6..f94760c 100644
--- a/libsoup/soup-auth-negotiate.c
+++ b/libsoup/soup-auth-negotiate.c
@@ -268,7 +268,7 @@ soup_auth_negotiate_update_connection (SoupConnectionAuth *auth, SoupMessage *ms
 		} else {
 			/* FIXME: report further upward via
 			 * soup_message_get_error_message  */
-			g_warning ("gssapi step failed: %s", err->message);
+			g_warning ("gssapi step failed: %s", err ? err->message : "Unknown error");
 			success = FALSE;
 		}
 	} else if (!strncmp (header, "Negotiate ", 10)) {
diff --git a/libsoup/soup-message-headers.c b/libsoup/soup-message-headers.c
index a180c6e..abef34c 100644
--- a/libsoup/soup-message-headers.c
+++ b/libsoup/soup-message-headers.c
@@ -1324,7 +1324,7 @@ content_type_setter (SoupMessageHeaders *hdrs, const char *value)
 {
 	g_free (hdrs->content_type);
 	if (value) {
-		char *content_type, *p;
+		char *content_type = NULL, *p;
 
 		parse_content_foo (hdrs, "Content-Type", &content_type, NULL);
 		p = strpbrk (content_type, " /");
diff --git a/libsoup/soup-xmlrpc.c b/libsoup/soup-xmlrpc.c
index 42dcda9..2da6344 100644
--- a/libsoup/soup-xmlrpc.c
+++ b/libsoup/soup-xmlrpc.c
@@ -588,7 +588,7 @@ signature_get_next_complete_type (const char **signature)
 
 			(*signature)++;
 
-			if ( (*signature)[0] == stack[stack_len - 1])
+			if ( stack_len > 0 && (*signature)[0] == stack[stack_len - 1])
 				stack_len--;
 		} while (stack_len > 0);
 
diff --git a/tests/test-utils.c b/tests/test-utils.c
index 9c74206..fc58362 100644
--- a/tests/test-utils.c
+++ b/tests/test-utils.c
@@ -676,6 +678,8 @@ soup_test_request_read_all (SoupRequest   *req,
 
 	if (!SOUP_IS_SESSION_SYNC (soup_request_get_session (req)))
 		data.loop = g_main_loop_new (g_main_context_get_thread_default (), FALSE);
+	else
+		data.loop = NULL;
 
 	do {
 		if (SOUP_IS_SESSION_SYNC (soup_request_get_session (req))) {
@@ -691,7 +695,7 @@ soup_test_request_read_all (SoupRequest   *req,
 		}
 	} while (nread > 0);
 
-	if (!SOUP_IS_SESSION_SYNC (soup_request_get_session (req)))
+	if (data.loop)
 		g_main_loop_unref (data.loop);
 
 	return nread == 0;