--- a/src/l_align.cc	Mon Sep 26 10:18:15 2011 +0300
+++ b/src/l_align.cc	Mon Sep 26 11:21:51 2011 +0300
@@ -164,7 +164,7 @@
     xoffset = 0;
     useroffset = 0;
 
-    if (!*sdlist)
+    if (*sdlist == NULL)
     {
         Notify(-1, -1, "Error in AlignTexturesX: list is empty", 0);
         return;
@@ -245,6 +245,7 @@
 
     /* Main processing loop */
     while (*sdlist)
+    while (*sdlist != NULL)
     {
         ldef = 0;
         sdef = (*sdlist)->objnum;
@@ -291,6 +292,7 @@
 
         /* do we test for same textures for the sidedef in question?? */
         sdef = (*sdlist)->objnum;
+        /* Check for contiguous textures, if required */
         if (opt_check)
         {
             SDPtr pdef = &SideDefs[sdef];
@@ -305,7 +307,7 @@
             }
         }
 
-        /* find out which linedef holds that sidedef */
+        /* Find out which linedef owns this sidedef */
         int n;
         for (ldef = -1, n = 0; n < NumLineDefs; n++)
             if ((opt_sdef == 1 && LineDefs[n].sidedef1 == sdef) ||
@@ -323,7 +325,7 @@
             return;
         }
 
-        /* test for linedef highlight continuity */
+        /* Test for linedef continuity */
         vert1 = LineDefs[ldef].start;
         if (vert1 != vert2 && vert2 != -1)
         {
@@ -341,16 +343,17 @@
             xoffset = opt_offset ? useroffset : 0;
         }
 
+        /* Set offset */
         SideDefs[sdef].xoff = xoffset;
 
-        /* calculate length of linedef */
+        /* Calculate length of linedef */
         vert2 = LineDefs[ldef].end;
         length = ComputeDist(Vertices[vert2].x - Vertices[vert1].x,
                              Vertices[vert2].y - Vertices[vert1].y);
 
         xoffset += length;
 
-        /* remove multiples of texlength from xoffset */
+        /* Remove multiples of texlength from xoffset */
         xoffset = xoffset % texlength;
 
         /* move to next object in selected list */