Fix for MDEV-12578: Connector/C doesn't read .my.cnf file in home dir…

…ectory.

After lookup in standard directories C/C now also checks in home directory for
configuration file .my.cnf

libmariadb/ma_default.c

@@ -30,19 +30,22 @@
 static const char *ini_exts[]= {"ini", "cnf", 0};
 static const char *ini_dirs[]= {"C:", ".", 0};
 static const char *ini_env_dirs[]= {"WINDOWS", "HOMEPATH", 0};
+#define ENV_HOME_DIR "HOMEPATH"
 #define R_OK 4
 #else
 #include <unistd.h>
 static const char *ini_exts[]= {"cnf", 0};
 static const char *ini_dirs[]= {"/etc", "/etc/mysql", ".", 0};
 static const char *ini_env_dirs[]= {"HOME", "SYSCONFDIR", 0};
+#define ENV_HOME_DIR "HOME"
 #endif
 
 extern my_bool _mariadb_set_conf_option(MYSQL *mysql, const char *config_option, const char *config_value);
 
 char *_mariadb_get_default_file(char *filename, size_t length)
 {
   int dirs; int exts;
+  char *env;
 
   for (dirs= 0; ini_dirs[dirs]; dirs++)
   {
@@ -58,13 +61,23 @@ char *_mariadb_get_default_file(char *filename, size_t length)
   {
     for (exts= 0; ini_exts[exts]; exts++)
     {
-      char *env= getenv(ini_env_dirs[dirs]);
+      env= getenv(ini_env_dirs[dirs]);
       snprintf(filename, length,
                "%s%cmy.%s", env, FN_LIBCHAR, ini_exts[exts]);
       if (!access(filename, R_OK))
         return filename;
     }
   }
+
+  /* check for .my file in home directoy */
+  env= getenv(ENV_HOME_DIR);
+  for (exts= 0; ini_exts[exts]; exts++)
+  {
+    snprintf(filename, length,
+             "%s%c.my.%s", env, FN_LIBCHAR, ini_exts[exts]);
+    if (!access(filename, R_OK))
+      return filename;
+  }
   return NULL;
 }
 

unittest/libmariadb/my_test.h

@@ -454,10 +454,13 @@ void get_envvars() {
 
   if (!hostname && (envvar= getenv("MYSQL_TEST_HOST")))
     hostname= envvar;
-  if (!username && (envvar= getenv("MYSQL_TEST_USER")))
-    username= envvar;
-  else
-    username= (char *)"root";
+  if (!username)
+  {
+    if ((envvar= getenv("MYSQL_TEST_USER")))
+      username= envvar;
+    else
+      username= (char *)"root";
+  }
   if (!password && (envvar= getenv("MYSQL_TEST_PASSWD")))
     password= envvar;
   if (!schema && (envvar= getenv("MYSQL_TEST_DB")))