Fix GCC 10.2.0 -Og -Wmaybe-uninitialized

For some reason, GCC emits more -Wmaybe-uninitialized warnings
when using the flag -Og than when using -O2. Many of the warnings
look genuine.

extra/mariabackup/backup_copy.cc

@@ -1786,7 +1786,7 @@ apply_log_finish()
 bool
 copy_back()
 {
-	bool ret;
+	bool ret = false;
 	datadir_iter_t *it = NULL;
 	datadir_node_t node;
 	char *dst_dir;

plugin/server_audit/server_audit.c

@@ -1428,7 +1428,6 @@ static size_t escape_string_hide_passwords(const char *str, unsigned int len,
   const char *res_start= result;
   const char *res_end= result + result_len - 2;
   size_t d_len;
-  char b_char;
 
   while (len)
   {
@@ -1466,27 +1465,28 @@ static size_t escape_string_hide_passwords(const char *str, unsigned int len,
 
       if (*next_s)
       {
-        memmove(result + d_len, "*****", 5);
+        const char b_char= *next_s++;
+        memset(result + d_len, '*', 5);
         result+= d_len + 5;
-        b_char= *(next_s++);
-      }
-      else
-        result+= d_len;
 
-      while (*next_s)
-      {
-        if (*next_s == b_char)
-        {
-          ++next_s;
-          break;
-        }
-        if (*next_s == '\\')
+        while (*next_s)
         {
-          if (next_s[1])
-            next_s++;
+          if (*next_s == b_char)
+          {
+            ++next_s;
+            break;
+          }
+          if (*next_s == '\\')
+          {
+            if (next_s[1])
+              next_s++;
+          }
+          next_s++;
         }
-        next_s++;
       }
+      else
+        result+= d_len;
+
       len-= (uint)(next_s - str);
       str= next_s;
       continue;
@@ -1494,19 +1494,23 @@ static size_t escape_string_hide_passwords(const char *str, unsigned int len,
 no_password:
     if (result >= res_end)
       break;
-    if ((b_char= escaped_char(*str)))
+    else
     {
-      if (result+1 >= res_end)
-        break;
-      *(result++)= '\\';
-      *(result++)= b_char;
+      const char b_char= escaped_char(*str);
+      if (b_char)
+      {
+        if (result+1 >= res_end)
+          break;
+        *(result++)= '\\';
+        *(result++)= b_char;
+      }
+      else if (is_space(*str))
+        *(result++)= ' ';
+      else
+        *(result++)= *str;
+      str++;
+      len--;
     }
-    else if (is_space(*str))
-      *(result++)= ' ';
-    else
-      *(result++)= *str;
-    str++;
-    len--;
   }
   *result= 0;
   return result - res_start;

sql/item.cc

 /*
    Copyright (c) 2000, 2018, Oracle and/or its affiliates.
-   Copyright (c) 2010, 2018, MariaDB Corporation
+   Copyright (c) 2010, 2020, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -7212,7 +7212,6 @@ Item *find_producing_item(Item *item, st_select_lex *sel)
   DBUG_ASSERT(item->type() == Item::FIELD_ITEM ||
               (item->type() == Item::REF_ITEM &&
                ((Item_ref *) item)->ref_type() == Item_ref::VIEW_REF)); 
-  Item *producing_item;
   Item_field *field_item= NULL;
   Item_equal *item_equal= item->get_item_equal();
   table_map tab_map= sel->master_unit()->derived->table->map;
@@ -7234,6 +7233,7 @@ Item *find_producing_item(Item *item, st_select_lex *sel)
   List_iterator_fast<Item> li(sel->item_list);
   if (field_item)
   {
+    Item *producing_item= NULL;
     uint field_no= field_item->field->field_index;
     for (uint i= 0; i <= field_no; i++)
       producing_item= li++;

sql/item_geofunc.cc

@@ -2389,12 +2389,15 @@ double Item_func_distance::val_real()
   MBR mbr1, mbr2;
   const char *c_end;
 
-
-  if ((null_value= (args[0]->null_value || args[1]->null_value ||
-          !(g1= Geometry::construct(&buffer1, res1->ptr(), res1->length())) ||
-          !(g2= Geometry::construct(&buffer2, res2->ptr(), res2->length())) ||
-          g1->get_mbr(&mbr1, &c_end) ||
-          g2->get_mbr(&mbr2, &c_end))))
+  if (args[0]->null_value || args[1]->null_value)
+    goto mem_error;
+  g1= Geometry::construct(&buffer1, res1->ptr(), res1->length());
+  if (!g1)
+    goto mem_error;
+  g2= Geometry::construct(&buffer2, res2->ptr(), res2->length());
+  if (!g2)
+    goto mem_error;
+  if (g1->get_mbr(&mbr1, &c_end) || g2->get_mbr(&mbr2, &c_end))
     goto mem_error;
 
   mbr1.add_mbr(&mbr2);
@@ -2543,7 +2546,7 @@ String *Item_func_pointonsurface::val_str(String *str)
   Geometry *g;
   MBR mbr;
   const char *c_end;
-  double UNINIT_VAR(px), UNINIT_VAR(py), x0, y0;
+  double UNINIT_VAR(px), UNINIT_VAR(py), x0, UNINIT_VAR(y0);
   String *result= 0;
   const Gcalc_scan_iterator::point *pprev= NULL;
   uint32 srid;

sql/mysqld.cc

@@ -6620,13 +6620,11 @@ void handle_connections_sockets()
   MYSQL_SOCKET sock= mysql_socket_invalid();
   MYSQL_SOCKET new_sock= mysql_socket_invalid();
   uint error_count=0;
-  CONNECT *connect;
   struct sockaddr_storage cAddr;
   int ip_flags __attribute__((unused))=0;
   int socket_flags __attribute__((unused))= 0;
   int extra_ip_flags __attribute__((unused))=0;
   int flags=0,retval;
-  bool is_unix_sock;
 #ifdef HAVE_POLL
   int socket_count= 0;
   struct pollfd fds[3]; // for ip_sock, unix_sock and extra_ip_sock
@@ -6826,41 +6824,37 @@ void handle_connections_sockets()
 
     DBUG_PRINT("info", ("Creating CONNECT for new connection"));
 
-    if ((connect= new CONNECT()))
+    if (CONNECT *connect= new CONNECT())
     {
-      is_unix_sock= (mysql_socket_getfd(sock) ==
-                     mysql_socket_getfd(unix_sock));
+      const bool is_unix_sock= (mysql_socket_getfd(sock) ==
+                                mysql_socket_getfd(unix_sock));
 
-      if (!(connect->vio=
-            mysql_socket_vio_new(new_sock,
-                                 is_unix_sock ? VIO_TYPE_SOCKET :
-                                 VIO_TYPE_TCPIP,
-                                 is_unix_sock ? VIO_LOCALHOST: 0)))
+      if ((connect->vio=
+           mysql_socket_vio_new(new_sock,
+                                is_unix_sock ? VIO_TYPE_SOCKET :
+                                VIO_TYPE_TCPIP,
+                                is_unix_sock ? VIO_LOCALHOST: 0)))
       {
-        delete connect;
-        connect= 0;                             // Error handling below
+        if (is_unix_sock)
+          connect->host= my_localhost;
+
+        if (mysql_socket_getfd(sock) == mysql_socket_getfd(extra_ip_sock))
+        {
+          connect->extra_port= 1;
+          connect->scheduler= extra_thread_scheduler;
+        }
+        create_new_thread(connect);
+        continue;
       }
-    }
 
-    if (!connect)
-    {
-      /* Connect failure */
-      (void) mysql_socket_shutdown(new_sock, SHUT_RDWR);
-      (void) mysql_socket_close(new_sock);
-      statistic_increment(aborted_connects,&LOCK_status);
-      statistic_increment(connection_errors_internal, &LOCK_status);
-      continue;
+      delete connect;
     }
 
-    if (is_unix_sock)
-      connect->host= my_localhost;
-
-    if (mysql_socket_getfd(sock) == mysql_socket_getfd(extra_ip_sock))
-    {
-      connect->extra_port= 1;
-      connect->scheduler= extra_thread_scheduler;
-    }
-    create_new_thread(connect);
+    /* Connect failure */
+    (void) mysql_socket_shutdown(new_sock, SHUT_RDWR);
+    (void) mysql_socket_close(new_sock);
+    statistic_increment(aborted_connects,&LOCK_status);
+    statistic_increment(connection_errors_internal, &LOCK_status);
   }
   sd_notify(0, "STOPPING=1\n"
             "STATUS=Shutdown in progress\n");

sql/sql_time.cc

@@ -358,7 +358,7 @@ static bool number_to_time_with_warn(bool neg, ulonglong nr, ulong sec_part,
   int was_cut;
   longlong res;
   enum_field_types f_type;
-  bool have_warnings;
+  bool have_warnings= false;
 
   if (fuzzydate & TIME_TIME_ONLY)
   {

storage/innobase/fts/fts0que.cc

@@ -2742,7 +2742,7 @@ fts_query_phrase_search(
 
 	/* Ignore empty strings. */
 	if (num_token > 0) {
-		fts_string_t*	token;
+		fts_string_t*	token = NULL;
 		fts_fetch_t	fetch;
 		trx_t*		trx = query->trx;
 		fts_ast_oper_t	oper = query->oper;

storage/maria/ma_create.c

@@ -75,7 +75,7 @@ int maria_create(const char *name, enum data_file_type datafile_type,
   uint max_field_lengths, extra_header_size, column_nr;
   uint internal_table= flags & HA_CREATE_INTERNAL_TABLE;
   ulong reclength, real_reclength,min_pack_length;
-  char kfilename[FN_REFLEN], klinkname[FN_REFLEN], *klinkname_ptr;
+  char kfilename[FN_REFLEN], klinkname[FN_REFLEN], *klinkname_ptr= NullS;
   char dfilename[FN_REFLEN], dlinkname[FN_REFLEN], *dlinkname_ptr= 0;
   ulong pack_reclength;
   ulonglong tot_length,max_rows, tmp;
@@ -889,7 +889,6 @@ int maria_create(const char *name, enum data_file_type datafile_type,
     fn_format(kfilename, name, "", MARIA_NAME_IEXT,
               MY_UNPACK_FILENAME | MY_RETURN_REAL_PATH |
               (have_iext ? MY_REPLACE_EXT : MY_APPEND_EXT));
-    klinkname_ptr= NullS;
     /*
       Replace the current file.
       Don't sync dir now if the data file has the same path.

storage/maria/ma_loghandler.c

@@ -3614,7 +3614,8 @@ my_bool translog_init_with_table(const char *directory,
   int old_log_was_recovered= 0, logs_found= 0;
   uint old_flags= flags;
   uint32 start_file_num= 1;
-  TRANSLOG_ADDRESS sure_page, last_page, last_valid_page, checkpoint_lsn;
+  TRANSLOG_ADDRESS UNINIT_VAR(sure_page), last_page, last_valid_page,
+    checkpoint_lsn;
   my_bool version_changed= 0;
   DBUG_ENTER("translog_init_with_table");
 

storage/myisam/mi_create.c

@@ -46,7 +46,7 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
   uint aligned_key_start, block_length, res;
   uint internal_table= flags & HA_CREATE_INTERNAL_TABLE;
   ulong reclength, real_reclength,min_pack_length;
-  char kfilename[FN_REFLEN],klinkname[FN_REFLEN], *klinkname_ptr;
+  char kfilename[FN_REFLEN],klinkname[FN_REFLEN], *klinkname_ptr= 0;
   char dfilename[FN_REFLEN],dlinkname[FN_REFLEN], *dlinkname_ptr= 0;
   ulong pack_reclength;
   ulonglong tot_length,max_rows, tmp;
@@ -622,7 +622,6 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
     fn_format(kfilename, name, "", MI_NAME_IEXT,
               MY_UNPACK_FILENAME | MY_RETURN_REAL_PATH |
               (have_iext ? MY_REPLACE_EXT : MY_APPEND_EXT));
-    klinkname_ptr= 0;
     /* Replace the current file */
     create_flag=(flags & HA_CREATE_KEEP_FILES) ? 0 : MY_DELETE_OLD;
   }

strings/ctype-ucs2.c

@@ -827,7 +827,7 @@ my_strtoll10_mb2(CHARSET_INFO *cs __attribute__((unused)),
                  const char *nptr, char **endptr, int *error)
 {
   const uchar *s, *end, *start, *n_end, *true_end;
-  uchar c;
+  uchar UNINIT_VAR(c);
   unsigned long i, j, k;
   ulonglong li;
   int negative;