Compile Reproduction
--------------------
Compile with GD 2.0.4
Will fail out with:
---
In file included from gd.c:83:
gd_ctx.c: In function `_php_image_output_ctx':
gd_ctx.c:70: structure has no member named `free'
gd_ctx.c:98: structure has no member named `free'
gd.c: In function `_php_image_type':
gd.c:1014: structure has no member named `free'
gd.c:1017: structure has no member named `free'
gd.c: In function `_php_image_create_from':
gd.c:1209: structure has no member named `free'
make[3]: *** [gd.lo] Error 1
make[3]: Leaving directory `/home/pub/system/daemons/apache/24102002/mods/php-4.2.3/ext/gd'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/home/pub/system/daemons/apache/24102002/mods/php-4.2.3/ext/gd'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/pub/system/daemons/apache/24102002/mods/php-4.2.3/ext'
make: *** [all-recursive] Error 1
---

Compile arguments
-----------------
./configure --with-apache=../../apache_1.3.27 --enable-track-var         --with-mysql --with-gd=/usr/local         --with-jpeg-dir=/usr/local --with-zlib --with-zlib-dir=/usr/local --with-png-dir=/usr/local

DIFFs
-----
# `diff ext/gd/gd.c ext/gd/gd.c-4.2.3`:
1014c1014
<                               io_ctx->gd_free(io_ctx);
---
>                               io_ctx->free(io_ctx);
1017c1017
<                               io_ctx->gd_free(io_ctx);
---
>                               io_ctx->free(io_ctx);
1209c1209
<               io_ctx->gd_free(io_ctx);
---
>               io_ctx->free(io_ctx);

# `diff ext/gd/gd_ctx.c ext/gd/gd_ctx.c-4.2.3`
70c70
<               ctx->gd_free = _php_image_output_ctxfree;
---
>               ctx->free = _php_image_output_ctxfree;
98c98
<       ctx->gd_free(ctx);
---
>       ctx->free(ctx);

Solution
--------
The diff changes allowed the compile to go through. Apparently, the  method free() was renamed to gd_free().