Cross-compiling GIMP 2.7 to Windows.

Hello!
When I try to cross-compile GIMP 2.6.11 or 2.7.1 to Windows, using MinGW, I get following errors:
file-png.c: In function 'on_read_error':
file-png.c:655:19: error: dereferencing pointer to incomplete type
file-png.c: In function 'load_image':
file-png.c:699:7: error: dereferencing pointer to incomplete type
file-png.c:740:11: error: dereferencing pointer to incomplete type
file-png.c:745:11: error: dereferencing pointer to incomplete type
file-png.c:745:54: error: dereferencing pointer to incomplete type
file-png.c:750:11: error: dereferencing pointer to incomplete type
file-png.c:750:57: error: dereferencing pointer to incomplete type
file-png.c:759:11: error: dereferencing pointer to incomplete type
file-png.c:760:12: error: dereferencing pointer to incomplete type
file-png.c:777:11: error: dereferencing pointer to incomplete type
file-png.c:799:15: error: dereferencing pointer to incomplete type
file-png.c:838:31: error: dereferencing pointer to incomplete type
file-png.c:838:44: error: dereferencing pointer to incomplete type
file-png.c:851:55: error: dereferencing pointer to incomplete type
file-png.c:851:68: error: dereferencing pointer to incomplete type
file-png.c:885:33: error: dereferencing pointer to incomplete type
file-png.c:885:67: error: dereferencing pointer to incomplete type
file-png.c:939:11: error: dereferencing pointer to incomplete type
file-png.c:947:19: error: dereferencing pointer to incomplete type
file-png.c:947:19: error: dereferencing pointer to incomplete type
file-png.c:949:59: error: dereferencing pointer to incomplete type
file-png.c:950:40: error: dereferencing pointer to incomplete type
file-png.c:954:58: error: dereferencing pointer to incomplete type
file-png.c:955:40: error: dereferencing pointer to incomplete type
file-png.c:973:11: error: dereferencing pointer to incomplete type
file-png.c:977:29: error: dereferencing pointer to incomplete type
file-png.c:977:43: error: dereferencing pointer to incomplete type
file-png.c:983:32: error: dereferencing pointer to incomplete type
file-png.c:984:32: error: dereferencing pointer to incomplete type
file-png.c:997:24: error: dereferencing pointer to incomplete type
file-png.c:999:25: error: dereferencing pointer to incomplete type
file-png.c:1000:23: error: dereferencing pointer to incomplete type
file-png.c:1017:47: error: dereferencing pointer to incomplete type
file-png.c:1020:64: error: dereferencing pointer to incomplete type
file-png.c:1076:5: warning: passing argument 5 of 'png_get_iCCP' from incompatible pointer type [enabled by default]
/usr/i686-w64-mingw32/sys-root/mingw/include/libpng15/png.h:1875:1: note: expected 'png_bytepp' but argument is of type 'char **'
file-png.c: In function 'save_image':
file-png.c:1209:13: warning: unused variable 'text_length' [-Wunused-variable]
file-png.c:1250:7: error: dereferencing pointer to incomplete type
file-png.c:1292:7: error: dereferencing pointer to incomplete type
file-png.c:1293:7: error: dereferencing pointer to incomplete type
file-png.c:1294:7: error: dereferencing pointer to incomplete type
file-png.c:1295:7: error: dereferencing pointer to incomplete type
file-png.c:1310:11: error: dereferencing pointer to incomplete type
file-png.c:1315:11: error: dereferencing pointer to incomplete type
file-png.c:1320:11: error: dereferencing pointer to incomplete type
file-png.c:1325:11: error: dereferencing pointer to incomplete type
file-png.c:1331:11: error: dereferencing pointer to incomplete type
file-png.c:1332:11: error: dereferencing pointer to incomplete type
file-png.c:1333:11: error: dereferencing pointer to incomplete type
file-png.c:1335:11: error: dereferencing pointer to incomplete type
file-png.c:1340:11: error: dereferencing pointer to incomplete type
file-png.c:1354:11: error: dereferencing pointer to incomplete type
file-png.c:1356:15: error: dereferencing pointer to incomplete type
file-png.c:1357:13: error: dereferencing pointer to incomplete type
file-png.c:1358:20: error: dereferencing pointer to incomplete type
file-png.c:1359:13: error: dereferencing pointer to incomplete type
file-png.c:1360:20: error: dereferencing pointer to incomplete type
file-png.c:1361:13: error: dereferencing pointer to incomplete type
file-png.c:1452:23: warning: pointer targets in passing argument 5 of 'png_set_iCCP' differ in signedness [-Wpointer-sign]
/usr/i686-w64-mingw32/sys-root/mingw/include/libpng15/png.h:1882:1: note: expected 'png_const_bytep' but argument is of type 'gchar *'
file-png.c:1478:11: error: dereferencing pointer to incomplete type
file-png.c:1478:57: error: dereferencing pointer to incomplete type
file-png.c:1530:19: error: dereferencing pointer to incomplete type
file-png.c:1550:24: error: dereferencing pointer to incomplete type
file-png.c:1565:47: error: dereferencing pointer to incomplete type
I have libpng 1.5.1-2.14 installed.