fc-scan: add --sysroot option

and fix scanning to get things work with sysroot

Fixes https://gitlab.freedesktop.org/fontconfig/fontconfig/-/issues/225

fc-scan/fc-scan.c

@@ -66,6 +66,7 @@
 static const struct option longopts[] = {
     {"brief", 0, 0, 'b'},
     {"format", 1, 0, 'f'},
+    {"sysroot", required_argument, 0, 'y'},
     {"version", 0, 0, 'V'},
     {"help", 0, 0, 'h'},
     {NULL,0,0,0},
@@ -82,10 +83,10 @@ usage (char *program, int error)
 {
     FILE *file = error ? stderr : stdout;
 #if HAVE_GETOPT_LONG
-    fprintf (file, _("usage: %s [-bVh] [-f FORMAT] [--brief] [--format FORMAT] [--version] [--help] font-file...\n"),
+    fprintf (file, _("usage: %s [-bcVh] [-f FORMAT] [-y SYSROOT] [--brief] [--format FORMAT] [--version] [--help] font-file...\n"),
 	     program);
 #else
-    fprintf (file, _("usage: %s [-bVh] [-f FORMAT] font-file...\n"),
+    fprintf (file, _("usage: %s [-bcVh] [-f FORMAT] [-y SYSROOT] font-file...\n"),
 	     program);
 #endif
     fprintf (file, _("Scan font files and directories, and print resulting pattern(s)\n"));
@@ -93,11 +94,13 @@ usage (char *program, int error)
 #if HAVE_GETOPT_LONG
     fprintf (file, _("  -b, --brief            display font pattern briefly\n"));
     fprintf (file, _("  -f, --format=FORMAT    use the given output format\n"));
+    fprintf (file, _("  -y, --sysroot=SYSROOT  prepend SYSROOT to all paths for scanning\n"));
     fprintf (file, _("  -V, --version          display font config version and exit\n"));
     fprintf (file, _("  -h, --help             display this help and exit\n"));
 #else
     fprintf (file, _("  -b         (brief)         display font pattern briefly\n"));
     fprintf (file, _("  -f FORMAT  (format)        use the given output format\n"));
+    fprintf (file, _("  -y SYSROOT (sysroot)       prepend SYSROOT to all paths for scanning\n"));
     fprintf (file, _("  -V         (version)       display font config version and exit\n"));
     fprintf (file, _("  -h         (help)          display this help and exit\n"));
 #endif
@@ -108,7 +111,7 @@ int
 main (int argc, char **argv)
 {
     int         brief = 0;
-    FcChar8     *format = NULL;
+    FcChar8     *format = NULL, *sysroot = NULL;
     int		i;
     FcFontSet   *fs;
 #if HAVE_GETOPT_LONG || HAVE_GETOPT
@@ -116,9 +119,9 @@ main (int argc, char **argv)
 
     setlocale (LC_ALL, "");
 #if HAVE_GETOPT_LONG
-    while ((c = getopt_long (argc, argv, "bf:Vh", longopts, NULL)) != -1)
+    while ((c = getopt_long (argc, argv, "bf:y:Vh", longopts, NULL)) != -1)
 #else
-    while ((c = getopt (argc, argv, "bf:Vh")) != -1)
+    while ((c = getopt (argc, argv, "bf:y:Vh")) != -1)
 #endif
     {
 	switch (c) {
@@ -128,6 +131,9 @@ main (int argc, char **argv)
 	case 'f':
 	    format = (FcChar8 *) strdup (optarg);
 	    break;
+	case 'y':
+	    sysroot = FcStrCopy ((const FcChar8 *) optarg);
+	    break;
 	case 'V':
 	    fprintf (stderr, "fontconfig version %d.%d.%d\n",
 		     FC_MAJOR, FC_MINOR, FC_REVISION);
@@ -146,6 +152,11 @@ main (int argc, char **argv)
     if (i == argc)
 	usage (argv[0], 1);
 
+    if (sysroot)
+    {
+	FcConfigSetSysRoot (NULL, sysroot);
+	FcStrFree (sysroot);
+    }
     fs = FcFontSetCreate ();
 
     for (; i < argc; i++)

src/Makefile.am

@@ -79,6 +79,7 @@ AM_CPPFLAGS = 						\
 	$(EXPAT_CFLAGS)					\
 	$(WARN_CFLAGS)					\
 	-DFC_CACHEDIR='"$(FC_CACHEDIR)"'                \
+	-DCONFIGDIR='"$(CONFIGDIR)"'			\
 	-DFONTCONFIG_PATH='"$(BASECONFIGDIR)"'		\
 	-DFC_TEMPLATEDIR='"$(TEMPLATEDIR)"'
 LDADD  = $(LIBINTL)

src/fccfg.c

@@ -2627,6 +2627,14 @@ FcConfigGetFilename (FcConfig      *config,
 
     if (FcStrIsAbsoluteFilename(url))
     {
+	if (sysroot)
+	{
+	    size_t len = strlen ((const char *) sysroot);
+
+	    /* Workaround to avoid adding sysroot repeatedly */
+	    if (strncmp ((const char *) url, (const char *) sysroot, len) == 0)
+		sysroot = NULL;
+	}
 	file = FcConfigFileExists (sysroot, url);
 	goto bail;
     }

src/fcdir.c

@@ -201,8 +201,9 @@ FcDirScanConfig (FcFontSet	*set,
     DIR			*d;
     struct dirent	*e;
     FcStrSet		*files;
-    FcChar8		*file;
+    FcChar8		*file_prefix, *s_dir = NULL;
     FcChar8		*base;
+    const FcChar8	*sysroot = FcConfigGetSysRoot (config);
     FcBool		ret = FcTrue;
     int			i;
 
@@ -213,20 +214,28 @@ FcDirScanConfig (FcFontSet	*set,
 	return FcTrue;
 
     /* freed below */
-    file = (FcChar8 *) malloc (strlen ((char *) dir) + 1 + FC_MAX_FILE_LEN + 1);
+    file_prefix = (FcChar8 *) malloc (strlen ((char *) dir) + 1 + FC_MAX_FILE_LEN + 1);
-    if (!file) {
+    if (!file_prefix) {
+	ret = FcFalse;
+	goto bail;
+    }
+    strcpy ((char *) file_prefix, (char *) dir);
+    strcat ((char *) file_prefix, FC_DIR_SEPARATOR_S);
+    base = file_prefix + strlen ((char *) file_prefix);
+
+    if (sysroot)
+	s_dir = FcStrBuildFilename (sysroot, dir, NULL);
+    else
+	s_dir = FcStrdup (dir);
+    if (!s_dir) {
 	ret = FcFalse;
 	goto bail;
     }
 
-    strcpy ((char *) file, (char *) dir);
-    strcat ((char *) file, "/");
-    base = file + strlen ((char *) file);
-
     if (FcDebug () & FC_DBG_SCAN)
-	printf ("\tScanning dir %s\n", dir);
+	printf ("\tScanning dir %s\n", s_dir);
 	
-    d = opendir ((char *) dir);
+    d = opendir ((char *) s_dir);
     if (!d)
     {
 	/* Don't complain about missing directories */
@@ -246,7 +255,7 @@ FcDirScanConfig (FcFontSet	*set,
 	if (e->d_name[0] != '.' && strlen (e->d_name) < FC_MAX_FILE_LEN)
 	{
 	    strcpy ((char *) base, (char *) e->d_name);
-	    if (!FcStrSetAdd (files, file)) {
+	    if (!FcStrSetAdd (files, file_prefix)) {
 		ret = FcFalse;
 		goto bail2;
 	    }
@@ -269,8 +278,10 @@ bail2:
 bail1:
     closedir (d);
 bail:
-    if (file)
+    if (s_dir)
-	free (file);
+	free (s_dir);
+    if (file_prefix)
+	free (file_prefix);
 
     return ret;
 }
@@ -339,7 +350,8 @@ FcDirCacheScan (const FcChar8 *dir, FcConfig *config)
     /*
      * Scan the dir
      */
-    if (!FcDirScanConfig (set, dirs, d, FcTrue, config))
+    /* Do not pass sysroot here. FcDirScanConfig() do take care of it */
+    if (!FcDirScanConfig (set, dirs, dir, FcTrue, config))
 	goto bail2;
 
     /*
@@ -404,7 +416,8 @@ FcDirCacheRescan (const FcChar8 *dir, FcConfig *config)
     /*
      * Scan the dir
      */
-    if (!FcDirScanConfig (NULL, dirs, d, FcTrue, config))
+    /* Do not pass sysroot here. FcDirScanConfig() do take care of it */
+    if (!FcDirScanConfig (NULL, dirs, dir, FcTrue, config))
 	goto bail1;
     /*
      * Rebuild the cache object