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		<title>al_read_directory crash on 64bit Windows 8</title>
		<link>http://www.allegro.cc/forums/view/611254</link>
		<description>Allegro.cc Forum Thread</description>
		<webMaster>matthew@allegro.cc (Matthew Leverton)</webMaster>
		<lastBuildDate>Mon, 15 Oct 2012 17:17:08 +0000</lastBuildDate>
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	<item>
		<description><![CDATA[<div class="mockup v2"><p>Hello,</p><p>I suspect there is a bug somewhere in al_read_directory code.. It could be related to 64bit setup as I am both using a 64bit Windows 8 RTM and have my project (and static Allegro 5.0.7 lib compiled as a 64bit binary). Here is the snipped I am having issues with:</p><div class="source-code"><div class="toolbar"><span class="button numbers"><b>#</b></span><span class="button select">Select</span><span class="button expand">Expand</span></div><div class="inner"><span class="number">  1</span><a href="http://www.allegro.cc/manual/ALLEGRO_FS_ENTRY"><span class="a">ALLEGRO_FS_ENTRY</span></a><span class="k3">*</span> resDir <span class="k3">=</span> <a href="http://www.allegro.cc/manual/al_create_fs_entry"><span class="a">al_create_fs_entry</span></a><span class="k2">(</span><span class="s">"D:\\Test\\"</span><span class="k2">)</span><span class="k2">;</span>
<span class="number">  2</span>
<span class="number">  3</span><span class="k1">if</span> <span class="k2">(</span><a href="http://www.allegro.cc/manual/al_open_directory"><span class="a">al_open_directory</span></a><span class="k2">(</span>resDir<span class="k2">)</span><span class="k2">)</span> <span class="k2">{</span>
<span class="number">  4</span>
<span class="number">  5</span>  <a href="http://www.allegro.cc/manual/ALLEGRO_FS_ENTRY"><span class="a">ALLEGRO_FS_ENTRY</span></a><span class="k3">*</span> nextFile<span class="k2">;</span>
<span class="number">  6</span>  <span class="k1">while</span> <span class="k2">(</span>nextFile <span class="k3">=</span> <a href="http://www.allegro.cc/manual/al_read_directory"><span class="a">al_read_directory</span></a><span class="k2">(</span>resDir<span class="k2">)</span><span class="k2">)</span> <span class="k2">{</span> <span class="c">// Crash</span>
<span class="number">  7</span>
<span class="number">  8</span>    <a href="http://www.allegro.cc/manual/al_destroy_fs_entry"><span class="a">al_destroy_fs_entry</span></a><span class="k2">(</span>nextFile<span class="k2">)</span><span class="k2">;</span>
<span class="number">  9</span>  <span class="k2">}</span>
<span class="number"> 10</span>    
<span class="number"> 11</span>  <a href="http://www.allegro.cc/manual/al_close_directory"><span class="a">al_close_directory</span></a><span class="k2">(</span>resDir<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 12</span><span class="k2">}</span>
<span class="number"> 13</span>
<span class="number"> 14</span><a href="http://www.allegro.cc/manual/al_destroy_fs_entry"><span class="a">al_destroy_fs_entry</span></a><span class="k2">(</span>resDir<span class="k2">)</span><span class="k2">;</span>
</div></div><p>

The &quot;D:\Test\&quot; directory exists (it passes the al_open_directory() call) and has some files/directories in it. The crash is access violation type (pointer issues?) and the stack dump points to ntdll.dll/findf64.c file.</p><p>I am using Visual Studio 2012 as my compiler/runtime.</p><p>Can anyone confirm it? Had similar issues before? Is there a possible workaround?</p><p><b>Edit:</b> It seems the crash is in Allegro fshook_stdio.c line 269 trying to call _tfindnext():</p><div class="source-code"><div class="toolbar"><span class="name">fshook_stdio.c</span><span class="button numbers"><b>#</b></span><span class="button select">Select</span><span class="button expand">Expand</span></div><div class="inner"><span class="number">  1</span><span class="c">/*</span>
<span class="number">  2</span><span class="c"> * readdir</span>
<span class="number">  3</span><span class="c"> *</span>
<span class="number">  4</span><span class="c"> * Return a pointer to a dirent structure filled with the information on the</span>
<span class="number">  5</span><span class="c"> * next entry in the directory.</span>
<span class="number">  6</span><span class="c"> */</span>
<span class="number">  7</span><span class="k1">static</span> <span class="k1">struct</span> dirent<span class="k3">*</span> <a href="http://www.delorie.com/djgpp/doc/libc/libc_646.html" target="_blank">readdir</a><span class="k2">(</span>DIR<span class="k3">*</span> dirp<span class="k2">)</span>
<span class="number">  8</span><span class="k2">{</span>
<span class="number">  9</span>   <a href="http://www.delorie.com/djgpp/doc/libc/libc_293.html" target="_blank">errno</a> <span class="k3">=</span> <span class="n">0</span><span class="k2">;</span>
<span class="number"> 10</span>
<span class="number"> 11</span>   <span class="c">/* Check for valid DIR struct. */</span>
<span class="number"> 12</span>   <span class="k1">if</span> <span class="k2">(</span><span class="k3">!</span>dirp<span class="k2">)</span> <span class="k2">{</span>
<span class="number"> 13</span>     <a href="http://www.delorie.com/djgpp/doc/libc/libc_293.html" target="_blank">errno</a> <span class="k3">=</span> EFAULT<span class="k2">;</span>
<span class="number"> 14</span>     <span class="k1">return</span> <span class="k2">(</span><span class="k1">struct</span> dirent<span class="k3">*</span><span class="k2">)</span> <span class="n">0</span><span class="k2">;</span>
<span class="number"> 15</span>   <span class="k2">}</span>
<span class="number"> 16</span>
<span class="number"> 17</span>   <span class="k1">if</span> <span class="k2">(</span>dirp-&gt;dd_stat <span class="k3">&lt;</span> <span class="n">0</span><span class="k2">)</span> <span class="k2">{</span>
<span class="number"> 18</span>      <span class="c">/* We have already returned all files in the directory</span>
<span class="number"> 19</span><span class="c">       * (or the structure has an invalid dd_stat). */</span>
<span class="number"> 20</span>      <span class="k1">return</span> <span class="k2">(</span><span class="k1">struct</span> dirent<span class="k3">*</span><span class="k2">)</span> <span class="n">0</span><span class="k2">;</span>
<span class="number"> 21</span>   <span class="k2">}</span>
<span class="number"> 22</span>   <span class="k1">else</span> <span class="k1">if</span> <span class="k2">(</span>dirp-&gt;dd_stat <span class="k3">=</span><span class="k3">=</span> <span class="n">0</span><span class="k2">)</span> <span class="k2">{</span>
<span class="number"> 23</span>      <span class="c">/* We haven't started the search yet. */</span>
<span class="number"> 24</span>      <span class="c">/* Start the search */</span>
<span class="number"> 25</span>      dirp-&gt;dd_handle <span class="k3">=</span> _tfindfirst<span class="k2">(</span>dirp-&gt;dd_name, <span class="k3">&amp;</span><span class="k2">(</span>dirp-&gt;dd_dta<span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 26</span>
<span class="number"> 27</span>      <span class="k1">if</span> <span class="k2">(</span>dirp-&gt;dd_handle <span class="k3">=</span><span class="k3">=</span> <span class="k3">-</span><span class="n">1</span><span class="k2">)</span> <span class="k2">{</span>
<span class="number"> 28</span>         <span class="c">/* Whoops! Seems there are no files in that</span>
<span class="number"> 29</span><span class="c">          * directory. */</span>
<span class="number"> 30</span>         dirp-&gt;dd_stat <span class="k3">=</span> <span class="k3">-</span><span class="n">1</span><span class="k2">;</span>
<span class="number"> 31</span>      <span class="k2">}</span>
<span class="number"> 32</span>      <span class="k1">else</span> <span class="k2">{</span>
<span class="number"> 33</span>         dirp-&gt;dd_stat <span class="k3">=</span> <span class="n">1</span><span class="k2">;</span>
<span class="number"> 34</span>      <span class="k2">}</span>
<span class="number"> 35</span>   <span class="k2">}</span>
<span class="number"> 36</span>   <span class="k1">else</span> <span class="k2">{</span>
<span class="number"> 37</span>      <span class="c">/* Get the next search entry. */</span>
<div class="highlight"><span class="number"> 38</span>      <span class="k1">if</span> <span class="k2">(</span>_tfindnext<span class="k2">(</span>dirp-&gt;dd_handle, <span class="k3">&amp;</span><span class="k2">(</span>dirp-&gt;dd_dta<span class="k2">)</span><span class="k2">)</span><span class="k2">)</span> <span class="k2">{</span></div><span class="number"> 39</span>         <span class="c">/* We are off the end or otherwise error.  </span>
<span class="number"> 40</span><span class="c">            _findnext sets errno to ENOENT if no more file</span>
<span class="number"> 41</span><span class="c">            Undo this. */</span> 
<span class="number"> 42</span>         DWORD winerr <span class="k3">=</span> GetLastError<span class="k2">(</span><span class="k2">)</span><span class="k2">;</span>
<span class="number"> 43</span>         <span class="k1">if</span> <span class="k2">(</span>winerr <span class="k3">=</span><span class="k3">=</span> ERROR_NO_MORE_FILES<span class="k2">)</span>
<span class="number"> 44</span>            <a href="http://www.delorie.com/djgpp/doc/libc/libc_293.html" target="_blank">errno</a> <span class="k3">=</span> <span class="n">0</span><span class="k2">;</span>  
<span class="number"> 45</span>         _findclose<span class="k2">(</span>dirp-&gt;dd_handle<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 46</span>         dirp-&gt;dd_handle <span class="k3">=</span> <span class="k3">-</span><span class="n">1</span><span class="k2">;</span>
<span class="number"> 47</span>         dirp-&gt;dd_stat <span class="k3">=</span> <span class="k3">-</span><span class="n">1</span><span class="k2">;</span>
<span class="number"> 48</span>      <span class="k2">}</span>
<span class="number"> 49</span>      <span class="k1">else</span> <span class="k2">{</span>
<span class="number"> 50</span>         <span class="c">/* Update the status to indicate the correct</span>
<span class="number"> 51</span><span class="c">          * number. */</span>
<span class="number"> 52</span>         dirp-&gt;dd_stat<span class="k3">+</span><span class="k3">+</span><span class="k2">;</span>
<span class="number"> 53</span>      <span class="k2">}</span>
<span class="number"> 54</span>   <span class="k2">}</span>
<span class="number"> 55</span>
<span class="number"> 56</span>   <span class="k1">if</span> <span class="k2">(</span>dirp-&gt;dd_stat <span class="k3">&gt;</span> <span class="n">0</span><span class="k2">)</span> <span class="k2">{</span>
<span class="number"> 57</span>      <span class="c">/* Successfully got an entry. Everything about the file is</span>
<span class="number"> 58</span><span class="c">       * already appropriately filled in except the length of the</span>
<span class="number"> 59</span><span class="c">       * file name. */</span>
<span class="number"> 60</span>      dirp-&gt;dd_dir.d_namlen <span class="k3">=</span> _tcslen<span class="k2">(</span>dirp-&gt;dd_dta.name<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 61</span>      _tcscpy<span class="k2">(</span>dirp-&gt;dd_dir.d_name, dirp-&gt;dd_dta.name<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 62</span>      <span class="k1">return</span> <span class="k3">&amp;</span>dirp-&gt;dd_dir<span class="k2">;</span>
<span class="number"> 63</span>   <span class="k2">}</span>
<span class="number"> 64</span>
<span class="number"> 65</span>   <span class="k1">return</span> <span class="k2">(</span><span class="k1">struct</span> dirent<span class="k3">*</span><span class="k2">)</span> <span class="n">0</span><span class="k2">;</span>
<span class="number"> 66</span><span class="k2">}</span>
</div></div><p>
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (simast)</author>
		<pubDate>Mon, 15 Oct 2012 17:17:08 +0000</pubDate>
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