diff -Naur kdelibs.orig/kio/kio/kmimemagic.cpp kdelibs/kio/kio/kmimemagic.cpp
--- kdelibs.orig/kio/kio/kmimemagic.cpp	2011-08-11 04:30:08.000000000 +0200
+++ kdelibs/kio/kio/kmimemagic.cpp	2011-11-19 23:23:41.000000000 +0100
@@ -1988,8 +1988,9 @@
 	return 1;
 }
 
-/* Maximal length of a line we consider "reasonable". */
-#define TEXT_MAXLINELEN 300
+/* Code removed below: conf files with big lines ARE text files,
+ * there is no "reasonable" length
+ */
 
 // This code is taken from the "file" command, where it is licensed
 // in the "beer-ware license" :-)
@@ -2007,23 +2008,6 @@
         if ((*cp < 8) || (*cp>13 && *cp<32 && *cp!=27 ) || (*cp==0x7F))
             return 0;
 
-    /* Now, look whether the file consists of lines of
-     * "reasonable" length. */
-
-    for (i = 0; i < nbytes;) {
-        cp = (unsigned char *) memchr(buf, '\n', nbytes - i);
-        if (cp == NULL) {
-            /* Don't fail if we hit the end of buffer. */
-            if (i + TEXT_MAXLINELEN >= nbytes)
-                break;
-            else
-                return 0;
-        }
-        if (cp - buf > TEXT_MAXLINELEN)
-            return 0;
-        i += (cp - buf + 1);
-        buf = cp + 1;
-    }
     conf->resultBuf = MIME_TEXT_PLAIN;
     return 1;
 }