From 08a05d3ab95a630e35cbdd16a2a7cef066ca6e92 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20M=C3=A4kel=C3=A4?= <markus.makela@mariadb.com>
Date: Wed, 6 Feb 2019 14:10:19 +0200
Subject: [PATCH] Fix use of uninitialized variables

Building with optimization in debug mode revealed code that could in
theory result in undefined behavior.
---
 include/maxscale/router.hh                                  | 2 +-
 server/modules/filter/cache/test/testkeygeneration.cc       | 2 +-
 server/modules/filter/hintfilter/hintparser.cc              | 4 +++-
 server/modules/filter/tpmfilter/tpmfilter.cc                | 2 +-
 .../protocol/MySQL/mariadbclient/setsqlmodeparser.hh        | 2 +-
 server/modules/routing/avrorouter/avro_schema.cc            | 3 ++-
 server/modules/routing/binlogrouter/blr_master.cc           | 6 +++---
 7 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/include/maxscale/router.hh b/include/maxscale/router.hh
index 278cfc40f..b4eb1a5e8 100644
--- a/include/maxscale/router.hh
+++ b/include/maxscale/router.hh
@@ -149,7 +149,7 @@ public:
     static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* pInstance, MXS_SESSION* pSession)
     {
         RouterType* pRouter = static_cast<RouterType*>(pInstance);
-        RouterSessionType* pRouter_session;
+        RouterSessionType* pRouter_session = nullptr;
 
         MXS_EXCEPTION_GUARD(pRouter_session = pRouter->newSession(pSession));
 
diff --git a/server/modules/filter/cache/test/testkeygeneration.cc b/server/modules/filter/cache/test/testkeygeneration.cc
index f823e5c6e..b9ab5bec9 100644
--- a/server/modules/filter/cache/test/testkeygeneration.cc
+++ b/server/modules/filter/cache/test/testkeygeneration.cc
@@ -123,7 +123,7 @@ int test(StorageFactory& factory, istream& in)
 int main(int argc, char* argv[])
 {
     int rv = EXIT_FAILURE;
-    StorageFactory* pFactory;
+    StorageFactory* pFactory = nullptr;
     if ((argc == 2) || (argc == 3))
     {
         char* libdir = MXS_STRDUP("../../../../../query_classifier/qc_sqlite/");
diff --git a/server/modules/filter/hintfilter/hintparser.cc b/server/modules/filter/hintfilter/hintparser.cc
index e302eaa02..09a06f14d 100644
--- a/server/modules/filter/hintfilter/hintparser.cc
+++ b/server/modules/filter/hintfilter/hintparser.cc
@@ -131,7 +131,9 @@ HINT* hint_parser(HINT_SESSION* session, GWBUF* request)
     int len, residual, state;
     int found, escape, quoted, squoted;
     HINT* rval = NULL;
-    char* pname, * lvalue, * hintname = NULL;
+    char* pname = nullptr;
+    char* lvalue = nullptr;
+    char* hintname = nullptr;
     GWBUF* buf;
     HINT_TOKEN* tok;
     HINT_MODE mode = HM_EXECUTE;
diff --git a/server/modules/filter/tpmfilter/tpmfilter.cc b/server/modules/filter/tpmfilter/tpmfilter.cc
index 711e81779..7ec410382 100644
--- a/server/modules/filter/tpmfilter/tpmfilter.cc
+++ b/server/modules/filter/tpmfilter/tpmfilter.cc
@@ -740,7 +740,7 @@ static void destroyInstance(MXS_FILTER* instance)
 
 static void checkNamedPipe(TPM_INSTANCE* inst)
 {
-    int ret;
+    int ret = 0;
     char buffer[2];
     char buf[4096];
     char* named_pipe = inst->named_pipe;
diff --git a/server/modules/protocol/MySQL/mariadbclient/setsqlmodeparser.hh b/server/modules/protocol/MySQL/mariadbclient/setsqlmodeparser.hh
index a5a86412f..635469358 100644
--- a/server/modules/protocol/MySQL/mariadbclient/setsqlmodeparser.hh
+++ b/server/modules/protocol/MySQL/mariadbclient/setsqlmodeparser.hh
@@ -487,7 +487,7 @@ private:
     {
         result_t rv = IS_SET_SQL_MODE;
 
-        char c;
+        char c = *pSql_mode;
 
         do
         {
diff --git a/server/modules/routing/avrorouter/avro_schema.cc b/server/modules/routing/avrorouter/avro_schema.cc
index e0e95eff9..54eab9e67 100644
--- a/server/modules/routing/avrorouter/avro_schema.cc
+++ b/server/modules/routing/avrorouter/avro_schema.cc
@@ -58,7 +58,8 @@ bool json_extract_field_names(const char* filename, std::vector<Column>& columns
     bool rval = false;
     json_error_t err;
     err.text[0] = '\0';
-    json_t* obj, * arr;
+    json_t* obj;
+    json_t* arr = nullptr;
 
     if ((obj = json_load_file(filename, 0, &err)) && (arr = json_object_get(obj, "fields")))
     {
diff --git a/server/modules/routing/binlogrouter/blr_master.cc b/server/modules/routing/binlogrouter/blr_master.cc
index d06ca8948..cb081de60 100644
--- a/server/modules/routing/binlogrouter/blr_master.cc
+++ b/server/modules/routing/binlogrouter/blr_master.cc
@@ -3053,17 +3053,17 @@ void blr_handle_fake_gtid_list(ROUTER_INSTANCE* router,
 static bool blr_handle_missing_files(ROUTER_INSTANCE* router,
                                      char* new_file)
 {
-    char* fptr;
+    char* fptr = strrchr(new_file, '.');
     uint32_t new_fseqno;
     uint32_t curr_fseqno;
     char buf[BLRM_BINLOG_NAME_STR_LEN];
     char bigbuf[PATH_MAX + 1];
 
-    if (*new_file
-        && (fptr = strrchr(new_file, '.')) == NULL)
+    if (fptr == NULL)
     {
         return false;
     }
+
     if (router->fileroot)
     {
         MXS_FREE(router->fileroot);