ext/gd/tests/gh17373.phpt fails without freetype support in gd

[orlitzky]

Description

The new test in ext/gd/tests/gh17373.phpt can fail if gd (bundled or otherwise) does not have freetype support:

---- EXPECTED OUTPUT
int(0)
---- ACTUAL OUTPUT
Fatal error: Uncaught Error: Call to undefined function imagefttext() in /home/mjo/src/php-src.git/ext/gd/tests/gh17373.php:7
Stack trace:
#0 {main}
  thrown in /home/mjo/src/php-src.git/ext/gd/tests/gh17373.php on line 7
---- FAILED

For the bundled gd, there is the constant HAVE_GD_FREETYPE, but from config.m4 I infer that it probably only works with the bundled gd. Fixing it for the system gd is going to be a headache, because (much like png, webp, etc) libgd defines the associated freetype functions whether they work or not. For example,

#ifndef HAVE_LIBFREETYPE
...
BGD_DECLARE(char *) gdImageStringFT (gdImagePtr im, int *brect, int fg, const char *fontlist,
                                     double ptsize, double angle, int x, int y, const char *string)
{
	(void)im;
	(void)brect;
	(void)fg;
        (void)fontlist;
        (void)ptsize;
	(void)angle;
	(void)x;
	(void)y;
        (void)string;

        return "libgd was not built with FreeType font support\n";
}

We already have one clever autoconf macro for a similar purpose (image format detection), but the naming scheme and return value are different in this case.

PHP Version

git head

Operating System

No response

[cmb69]

Wouldn't the following do:

--SKIPIF--
if (!function_exists("imagefttext")) die("skip no freetype support");

[orlitzky]

On 2025-02-23 11:33:09, Christoph M. Becker wrote: cmb69 left a comment (php/php-src#17891) Wouldn't the following do: ```` --SKIPIF-- if (!function_exists("imagefttext")) die("skip no freetype support"); ````

Sadly no: this skips the test even if a system gd with freetype support is being used.

[cmb69]

Sadly no: this skips the test even if a system gd with freetype support is being used.

Then there would be a bug in ext/gd. If there is freetype support in libgd, the ext/gd function imagefttext() should be defined. Oh:

php-src/ext/gd/config.m4

Lines 196 to 199 in 1fa15ab

	PHP_CHECK_LIBRARY([gd], [gdFontCacheShutdown],
	[AC_DEFINE([HAVE_GD_FREETYPE], [1])],
	[],
	[$GD_SHARED_LIBADD])

looks hackish. We should not check for gdFontCacheShutdown(), but rather whether gdImageStringFT() returns something rather different from libgd was not built with FreeType font support.

PS: a "proper" libgd.pc should reveal the available features.

[orlitzky]

Hold on, I may just be lying. It's possible that gdFontCacheShutdown() is ifdef'd out much earlier in the file. I sat down to hack on this and have a growing suspicion that I did my earlier test while SSHed into my work PC.

[orlitzky]

Confirmed. Con: I'm an idiot. Pro: There's no need to write any autoconf macros.

#17891 (comment) is all it takes. Near certain I queried my gd package on the wrong machine.