Sort directory entries while scanning them from disk; prevents Heisenbugs

    due to file ordering in a directory.
reviewed by: plam

diff --git a/ChangeLog b/ChangeLog
index 5598eab27384485065c7a7d53f031253730545ba..b1835ed88ec14d44a6089c64c089404349d54fa2 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2006-03-08  Egmont Koblinger  <egmont@uhulinux.hu>
+       reviewed by: plam
+
+       * src/fcdir.c (FcDirScanConfig):
+
+       Sort directory entries while scanning them from disk;
+       prevents Heisenbugs due to file ordering in a directory.
+
 2006-03-07  Behdad Esfahbod  <behdad@cs.toronto.edu>
        reviewed by: plam
 

diff --git a/src/fcdir.c b/src/fcdir.c
index 7e59452d1f0f108b656af8755e917e29e62ba502..bc8322b487dde45d1b66e74eefcd6740f8649ccf 100644 (file)
--- a/src/fcdir.c
+++ b/src/fcdir.c
@@ -100,6 +100,16 @@ FcFileScan (FcFontSet          *set,
     return FcFileScanConfig (set, dirs, cache, blanks, file, force, 0);
 }
 
+/*
+ * Strcmp helper that takes pointers to pointers, copied from qsort(3) manpage
+ */
+
+static int
+cmpstringp(const void *p1, const void *p2)
+{
+    return strcmp(* (char **) p1, * (char **) p2);
+}
+
 /*
  * Scan 'dir', adding font files to 'set' and
  * subdirectories to 'dirs'
@@ -116,6 +126,8 @@ FcDirScanConfig (FcFontSet  *set,
 {
     DIR                        *d;
     struct dirent      *e;
+    FcChar8            **dirlist;
+    int                        dirlistlen, dirlistalloc;
     FcChar8            *file;
     const FcChar8      *d_can = 0;
     FcChar8            *base;
@@ -174,14 +186,40 @@ FcDirScanConfig (FcFontSet        *set,
        return FcFalse;
     }
 
-    while (ret && (e = readdir (d)))
+    dirlistlen = 0;
+    dirlistalloc = 8;
+    dirlist = malloc(dirlistalloc * sizeof(FcChar8 *));
+    if (!dirlist)
+       return FcFalse;
+    while ((e = readdir (d)))
     {
        if (e->d_name[0] != '.' && strlen (e->d_name) < FC_MAX_FILE_LEN)
        {
-           strcpy ((char *) base, (char *) e->d_name);
-           ret = FcFileScanConfig (tmpSet, dirs, cache, blanks, file, force, config);
+           if (dirlistlen == dirlistalloc)
+           {
+               dirlistalloc *= 2;
+               dirlist = realloc(dirlist, dirlistalloc * sizeof(FcChar8 *));
+               if (!dirlist)
+                   return FcFalse;
+           }
+           dirlist[dirlistlen] = malloc(strlen (e->d_name) + 1);
+           if (!dirlist[dirlistlen])
+               return FcFalse;
+           strcpy(dirlist[dirlistlen], e->d_name);
+           dirlistlen++;
        }
     }
+    qsort(dirlist, dirlistlen, sizeof(FcChar8 *), cmpstringp);
+    i = 0;
+    while (ret && i < dirlistlen)
+    {
+       strcpy ((char *) base, (char *) dirlist[i]);
+       ret = FcFileScanConfig (tmpSet, dirs, cache, blanks, file, force, config);
+       i++;
+    }
+    for (i = 0; i < dirlistlen; i++)
+       free(dirlist[i]);
+    free (dirlist);
     free (file);
     closedir (d);
     /*