Added build option WITH_ICONV.

Default is OFF, which means MariaDB Connector/C
will be built without iconv support.

If set to OFF The API function mariadb_convert_string will always
return -1 and errorcode ENOTSUP.

CMakeLists.txt

@@ -24,7 +24,7 @@ get_directory_property(IS_SUBPROJECT PARENT_DIRECTORY)
 # do not inherit include directories from the parent project
 SET_PROPERTY(DIRECTORY PROPERTY INCLUDE_DIRECTORIES)
 FOREACH(V WITH_MYSQLCOMPAT WITH_MSI WITH_SIGNCODE WITH_RTC WITH_UNIT_TESTS
-    WITH_DYNCOL WITH_EXTERNAL_ZLIB WITH_CURL WITH_SQLITE WITH_SSL
+    WITH_DYNCOL WITH_EXTERNAL_ZLIB WITH_CURL WITH_SQLITE WITH_SSL WITH_ICONV
     INSTALL_LAYOUT WITH_TEST_SRCPKG)
   SET(${V} ${${OPT}${V}})
 ENDFOREACH()
@@ -57,6 +57,7 @@ ELSE()
   ADD_OPTION(WITH_MSI "Build MSI installation package" OFF)
   ADD_OPTION(WITH_SIGNCODE "digitally sign files" OFF)
   ADD_OPTION(WITH_RTC "enables run time checks for debug builds" OFF)
+  ADD_OPTION(WITH_ICONV "enables character set conversion" OFF)
 ENDIF()
 
 ADD_OPTION(WITH_UNIT_TESTS "build test suite" ON)
@@ -343,8 +344,10 @@ ELSEIF (NOT ENABLED_LOCAL_INFILE MATCHES "^(ON|OFF|AUTO)$")
   MESSAGE(FATAL_ERROR "ENABLED_LOCAL_INFILE must be one of OFF, ON, AUTO")
 ENDIF()
 
-IF(NOT WIN32)
+IF(WITH_ICONV)
+  IF(NOT WIN32)
     INCLUDE(${CC_SOURCE_DIR}/cmake/FindIconv.cmake)
+  ENDIF()
 ENDIF()
 
 CONFIGURE_FILE(${CC_SOURCE_DIR}/include/ma_config.h.in

cmake/FindIconv.cmake

@@ -58,6 +58,7 @@ if (ICONV_FOUND)
     return 0;
   }
 " ICONV_SECOND_ARGUMENT_IS_CONST )
+  ADD_DEFINITIONS(-DHAVE_ICONV)
 endif (ICONV_FOUND)
 
 set (CMAKE_REQUIRED_INCLUDES)

libmariadb/ma_charset.c

@@ -53,11 +53,13 @@
 #include <mariadb_ctype.h>
 #include <ma_string.h>
 
+#ifdef HAVE_ICONV
 #ifdef _WIN32
 #include "../win-iconv/iconv.h"
 #else
 #include <iconv.h>
 #endif
+#endif
 
 
 #if defined(HAVE_NL_LANGINFO) && defined(HAVE_SETLOCALE)
@@ -1385,7 +1387,7 @@ int madb_get_windows_cp(const char *charset)
 #endif
 /* }}} */
 
-
+#ifdef HAVE_ICONV
 /* {{{ map_charset_name
    Changing charset name into something iconv understands, if necessary.
    Another purpose it to avoid BOMs in result string, adding BE if necessary
@@ -1413,6 +1415,7 @@ static void map_charset_name(const char *cs_name, my_bool target_cs, char *buffe
   }
 }
 /* }}} */
+#endif
 
 /* {{{ mariadb_convert_string
    Converts string from one charset to another, and writes converted string to given buffer
@@ -1426,9 +1429,17 @@ static void map_charset_name(const char *cs_name, my_bool target_cs, char *buffe
 
    @return -1 in case of error, bytes used in the "to" buffer, otherwise
  */
-size_t STDCALL mariadb_convert_string(const char *from, size_t *from_len, MARIADB_CHARSET_INFO *from_cs,
-                                      char *to, size_t *to_len, MARIADB_CHARSET_INFO *to_cs, int *errorcode)
+size_t STDCALL mariadb_convert_string(const char *from __attribute__((unused)),
+                                      size_t *from_len __attribute__((unused)),
+                                      MARIADB_CHARSET_INFO *from_cs __attribute__((unused)),
+                                      char *to __attribute__((unused)),
+                                      size_t *to_len __attribute__((unused)),
+                                      MARIADB_CHARSET_INFO *to_cs __attribute__((unused)), int *errorcode)
 {
+#ifndef HAVE_ICONV
+  *errorcode= ENOTSUP;
+  return -1;
+#else
   iconv_t conv= 0;
   size_t rc= -1;
   size_t save_len= *to_len;
@@ -1462,6 +1473,7 @@ error:
   if (conv != (iconv_t)-1)
     iconv_close(conv);
   return rc;
+#endif
 }
 /* }}} */
 

unittest/libmariadb/charset.c

@@ -661,6 +661,10 @@ static int test_bug_54100(MYSQL *mysql)
 
 static int test_utf16_utf32_noboms(MYSQL *mysql __attribute__((unused)))
 {
+#ifndef HAVE_ICONV
+  diag("MariaDB Connector/C was built without iconv support");
+  return SKIP;
+#else
   const char *csname[]= {"utf16", "utf16le", "utf32", "utf8"};
   MARIADB_CHARSET_INFO  *csinfo[sizeof(csname)/sizeof(char*)];
 
@@ -724,6 +728,7 @@ static int test_utf16_utf32_noboms(MYSQL *mysql __attribute__((unused)))
   }
 
   return OK;
+#endif
 }
 
 static int charset_auto(MYSQL *my __attribute__((unused)))