MDEV-6262 analyze the coverity report on mariadb

uploaded 10.0, analyzed everything with the Impact=High
(and a couple of Medium)

6 files changed, 20 insertions, 16 deletions

diff --git a/client/mysql.cc b/client/mysql.cc
index a9310a87d8e..3461f8bbc75 100644
--- a/client/mysql.cc
+++ b/client/mysql.cc
@@ -3061,7 +3061,6 @@ static int com_server_help(String *buffer __attribute__((unused)),
   {
     unsigned int num_fields= mysql_num_fields(result);
     my_ulonglong num_rows= mysql_num_rows(result);
-    mysql_fetch_fields(result);
     if (num_fields==3 && num_rows==1)
     {
       if (!(cur= mysql_fetch_row(result)))
diff --git a/client/mysql_upgrade.c b/client/mysql_upgrade.c
index f2d94871f07..397a252cdc0 100644
--- a/client/mysql_upgrade.c
+++ b/client/mysql_upgrade.c
@@ -1042,7 +1042,7 @@ static int check_version_match(void)
 
 int main(int argc, char **argv)
 {
-  char self_name[FN_REFLEN];
+  char self_name[FN_REFLEN + 1];
 
   MY_INIT(argv[0]);
 
@@ -1050,7 +1050,7 @@ int main(int argc, char **argv)
   if (GetModuleFileName(NULL, self_name, FN_REFLEN) == 0)
 #endif
   {
-    strncpy(self_name, argv[0], FN_REFLEN);
+    strmake_buf(self_name, argv[0]);
   }
 
   if (init_dynamic_string(&ds_args, "", 512, 256) ||
diff --git a/client/mysqladmin.cc b/client/mysqladmin.cc
index bab94d6e5ee..e85d306c834 100644
--- a/client/mysqladmin.cc
+++ b/client/mysqladmin.cc
@@ -614,6 +614,7 @@ static my_bool sql_connect(MYSQL *mysql, uint wait)
 
 static int execute_commands(MYSQL *mysql,int argc, char **argv)
 {
+  int ret = 0;
   const char *status;
   /*
     MySQL documentation relies on the fact that mysqladmin will
@@ -1107,7 +1108,8 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
         if (strcmp(typed_password, verified) != 0)
         {
           my_printf_error(0,"Passwords don't match",MYF(ME_BELL));
-          return -1;
+          ret = -1;
+          goto password_done;
         }
       }
       else
@@ -1134,7 +1136,8 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
           {
             my_printf_error(0, "Could not determine old_passwords setting from server; error: '%s'",
                 	    error_flags, mysql_error(mysql));
-            return -1;
+            ret = -1;
+            goto password_done;
           }
           else
           {
@@ -1145,7 +1148,8 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
                               "Could not get old_passwords setting from "
                               "server; error: '%s'",
         		      error_flags, mysql_error(mysql));
-              return -1;
+              ret = -1;
+              goto password_done;
             }
             if (!mysql_num_rows(res))
               old= 1;
@@ -1170,15 +1174,15 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
       {
 	my_printf_error(0, "Can't turn off logging; error: '%s'",
 			error_flags, mysql_error(mysql));
-	return -1;
+        ret = -1;
       }
+      else
       if (mysql_query(mysql,buff))
       {
 	if (mysql_errno(mysql)!=1290)
 	{
 	  my_printf_error(0,"unable to change password; error: '%s'",
 			  error_flags, mysql_error(mysql));
-	  return -1;
 	}
 	else
 	{
@@ -1192,9 +1196,10 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
 			  " --skip-grant-tables).\n"
 			  "Use: \"mysqladmin flush-privileges password '*'\""
 			  " instead", error_flags);
-	  return -1;
 	}
+        ret = -1;
       }
+password_done:
       /* free up memory from prompted password */
       if (typed_password != argv[1]) 
       {
@@ -1296,7 +1301,7 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
       return 1;
     }
   }
-  return 0;
+  return ret;
 }
 
 /**
diff --git a/client/mysqlbinlog.cc b/client/mysqlbinlog.cc
index 29355d013c7..804c6314ef9 100644
--- a/client/mysqlbinlog.cc
+++ b/client/mysqlbinlog.cc
@@ -1976,7 +1976,7 @@ static Exit_status dump_remote_log_entries(PRINT_EVENT_INFO *print_event_info,
   int2store(buf + BIN_LOG_HEADER_SIZE, binlog_flags);
 
   size_t tlen = strlen(logname);
-  if (tlen > UINT_MAX) 
+  if (tlen > sizeof(buf) - 10)
   {
     error("Log name too long.");
     DBUG_RETURN(ERROR_STOP);
diff --git a/client/mysqldump.c b/client/mysqldump.c
index 245f24dd508..6877a5cee3b 100644
--- a/client/mysqldump.c
+++ b/client/mysqldump.c
@@ -2818,6 +2818,8 @@ static uint get_table_structure(char *table, char *db, char *table_type,
 
           my_free(scv_buff);
 
+          if (path)
+            my_fclose(sql_file, MYF(MY_WME));
           DBUG_RETURN(0);
         }
         else
@@ -5827,8 +5829,7 @@ static my_bool get_view_structure(char *table, char* db)
     dynstr_free(&ds_view);
   }
 
-  if (switch_character_set_results(mysql, default_charset))
-    DBUG_RETURN(1);
+  switch_character_set_results(mysql, default_charset);
 
   /* If a separate .sql file was opened, close it now */
   if (sql_file != md_result_file)
diff --git a/client/mysqltest.cc b/client/mysqltest.cc
index d903484bd4d..f9715bfbfdb 100644
--- a/client/mysqltest.cc
+++ b/client/mysqltest.cc
@@ -1721,13 +1721,12 @@ void log_msg(const char *fmt, ...)
 int cat_file(DYNAMIC_STRING* ds, const char* filename)
 {
   int fd;
-  size_t len;
+  int len;
   char buff[16384];
 
   if ((fd= my_open(filename, O_RDONLY, MYF(0))) < 0)
     return 1;
-  while((len= my_read(fd, (uchar*)&buff,
-                      sizeof(buff)-1, MYF(0))) > 0)
+  while((len= (int)my_read(fd, (uchar*)&buff, sizeof(buff)-1, MYF(0))) > 0)
   {
     char *p= buff, *start= buff,*end=buff+len;
     while (p < end)