Skip Thai character test when libthai is unavailable.

Taken from upstream bug tracker:
https://gitlab.gnome.org/GNOME/pango/merge_requests/161
https://gitlab.gnome.org/GNOME/pango/commit/b73284747ac937e31dc9191f84ed6e24284c88ee

diff --git a/tests/test-break.c b/tests/test-break.c
index 8549b678bba69360d07dce3af21d915412f20d51..47fa3009165e19a331aa04a0df4351ae2323933b 100644
--- a/tests/test-break.c
+++ b/tests/test-break.c
@@ -305,6 +305,12 @@ main (int argc, char *argv[])
       if (!strstr (name, "break"))
         continue;
 
+#ifndef HAVE_LIBTHAI
+      /* four.break involves Thai, so only test it when we have libthai */
+      if (strstr (name, "four.break"))
+        continue;
+#endif
+
       path = g_strdup_printf ("/break/%s", name);
       g_test_add_data_func_full (path, g_test_build_filename (G_TEST_DIST, "breaks", name, NULL),
                                  test_break, g_free);
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<tr><td><span title='2020-03-16 14:05:52 +0100'>2020-03-16</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=a37e03d60e18dfcf119d0b92d9008e54fc350bf1'>tests: opensmtpd: Check /var/spool/mail instead of /var/mail.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-03-16 14:05:52 +0100'>2020-03-16</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=c215d9ec1ce108844b14c0c2952199a0da5f4176'>tests: opensmtpd: Gracefully handle test failure.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-03-09 23:46:36 +0100'>2020-03-09</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=827abd5deb87c1ec15112d7cde1a03a4ba4b4983'>tests: getmail: Provide a pre-initialized user account password.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-01-31 00:42:48 +0100'>2020-01-31</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=c3f146e79aca0efec5c0cbbf4e39c79e09268c15'>gnu: Update opensmtpd configuration grammar.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-01-20 19:13:17 +0000'>2020-01-20</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=b3e28b5ef5e23e564eeac8823ad2c837f7c40650'>tests: mail: Remove %getmail-os from the bottom of the file.</a><span class='msg-avail'>...</span></td><td>Christopher Baines</td></tr>
<tr><td><span title='2019-06-19 11:49:33 +0200'>2019-06-19</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=bf5929c5303511da338da894ce072c138fe8324f'>tests: Fix opensmtpd test.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-05-31 20:22:20 +0100'>2019-05-31</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=f6b0e1f8ff6a6459d7d39238ced165f4caa988fe'>services: Add getmail.</a><span class='msg-avail'>...</span></td><td>Christopher Baines</td></tr>
<tr><td><span title='2018-10-18 01:12:22 +0200'>2018-10-18</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=39d7fdce453b0ca23ecbed72048647debbaa58a6'>services: dhcp-client: Deprecate 'dhcp-client-service' procedure.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-06-13 09:11:45 +0200'>2018-06-13</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=c24b15472baaa7ec67d48cbf296bbe5ab727b78f'>tests: Honor the return value of 'start-service'.</a><span class='msg-avail'>...</span></td><td>Clément Lassieur</td></tr>
<tr><td><span title='2018-03-09 17:24:45 +0300'>2018-03-09</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=a9079b488037371f90514b82961dc075ea0b3985'>tests: mail: Add test for dovecot.</a><span class='msg-avail'>...</span></td><td>Oleg Pykhalov</td></tr>
<tr><td><span title='2017-07-20 11:57:13 +0200'>2017-07-20</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=8b113790fa3bfd2300c737901ba161f079fedbdf'>tests: Use 'virtual-machine' records instead of monadic procedures.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-04-19 23:43:50 +0200'>2017-04-19</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=950026ac7f17b3b4d5420cde9709c24e9af76dcb'>tests: mail: Add test for exim</a><span class='msg-avail'>...</span></td><td>Carlo Zancanaro</td></tr>
<tr><td><span title='2017-04-01 00:45:18 +0200'>2017-04-01</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=892d9089a88abaa2ef1127f16308d03f4f08a4ce'>tests: Introduce 'simple-operating-system' and use it.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2016-11-27 10:15:43 +0800'>2016-11-27</span></td><td><a href='/guix/commit/gnu/tests/mail.scm?id=a82f0b36177848eda340d880ae0802c3e26c4ea8'>tests: Add 'opensmtpd-service-type' test.</a><span class='msg-avail'>...</span></td><td>宋文武</td></tr>