By popular demand, merge my Debian patch adding support for dll.conf

snippets under $configdir/dll.d.

ChangeLog

@@ -1,5 +1,10 @@
 2008-05-07  Julien Blache <jb@jblache.org>
 	* doc/sane-config.man: Fix man warning.
+	* backend/dll.c: look for dll.conf snippets in
+	$configdir/dll.d; this is a facility for external backends
+	to automatically add their backends to the dll backend
+	configuration without mucking with dll.conf.
+	* backend/Makefile.in: create $configdir/dll.d.
 
 2008-05-07  Nicolas Martin <nicols-guest at users.alioth.debian.org>
 	* backend/pixma_imageclass.c, doc/descriptions/pixma.desc:

backend/Makefile.in

@@ -237,7 +237,7 @@ all:	$(LIBS) libsane.la becfg
 install: $(INSTALL_LOCKPATH) install-be@BE_INSTALL_FLAVOR@ install-libsane install-becfg
 
 install-be:
-	$(MKDIR) $(DESTDIR)$(libdir) $(DESTDIR)$(libsanedir) $(DESTDIR)$(configdir)
+	$(MKDIR) $(DESTDIR)$(libdir) $(DESTDIR)$(libsanedir) $(DESTDIR)$(configdir) $(DESTDIR)$(configdir)/dll.d
 	@# Install all backends in $(prefix)/lib/sane/
 	@list="$(LIBS)"; for be in $$list; do \
 	  echo installing $${be} in $(DESTDIR)$(libsanedir)/$${be}...; \
@@ -263,7 +263,7 @@ install-be:
 	fi
 
 install-be-beos:
-	$(MKDIR) $(DESTDIR)$(libdir) $(DESTDIR)$(libsanedir) $(DESTDIR)$(configdir) $(DESTDIR)$(BEOS_ADDONDIR)
+	$(MKDIR) $(DESTDIR)$(libdir) $(DESTDIR)$(libsanedir) $(DESTDIR)$(configdir) $(DESTDIR)$(configdir)/dll.d $(DESTDIR)$(BEOS_ADDONDIR)
 	@list="$(ALL_BACKENDS)"; for be in $$list; do \
 	  echo installing $${be} in $(BEOS_ADDONDIR)/$${be}...; \
 	  cp -p .libs/libsane-$${be}.so $(DESTDIR)$(BEOS_ADDONDIR)/$${be} || exit 1; \

backend/dll.c

@@ -95,6 +95,8 @@
 #endif
 
 #include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
 
 #include "sane/sane.h"
 #include "sane/sanei.h"
@@ -720,12 +722,113 @@ add_alias (const char *line_param)
 }
 
 
+static void
+read_config (const char *conffile)
+{
+  FILE *fp;
+  char config_line[PATH_MAX];
+  char *backend_name;
+
+  fp = sanei_config_open (conffile);
+  if (!fp)
+    {
+      DBG (1, "sane_init/read_config: Couldn't open config file (%s): %s\n",
+           conffile, strerror (errno));
+      return; /* don't insist on config file */
+    }
+
+  DBG (5, "sane_init/read_config: reading %s\n", conffile);
+  while (sanei_config_read (config_line, sizeof (config_line), fp))
+    {
+      char *comment;
+      SANE_String_Const cp;
+
+      cp = sanei_config_get_string (config_line, &backend_name);
+      /* ignore empty lines */
+      if (!backend_name || cp == config_line)
+        {
+          if (backend_name)
+            free (backend_name);
+          continue;
+        }
+      /* ignore line comments */
+      if (backend_name[0] == '#')
+        {
+          free (backend_name);
+          continue;
+        }
+      /* ignore comments after backend names */
+      comment = strchr (backend_name, '#');
+      if (comment)
+        *comment = '\0';
+      add_backend (backend_name, 0);
+      free (backend_name);
+    }
+  fclose (fp);
+}
+
+static void
+read_dlld (void)
+{
+  DIR *dlld;
+  struct dirent *dllconf;
+  struct stat st;
+  char conffile[PATH_MAX];
+  size_t len, plen;
+
+  DBG (5, "sane_init/read_dlld: processing %s ...\n",
+       STRINGIFY(PATH_SANE_CONFIG_DIR) "/dll.d");
+
+  /* Debian specific: read files under $sysconfdir/sane.d/dll.d */
+  dlld = opendir (STRINGIFY(PATH_SANE_CONFIG_DIR) "/dll.d");
+
+  if (dlld == NULL)
+    {
+      DBG (1, "sane_init/read_dlld: opendir failed: %s\n",
+           strerror (errno));
+      return;
+    }
+
+  plen = strlen (STRINGIFY(PATH_SANE_CONFIG_DIR)) + 1;
+
+  while ((dllconf = readdir (dlld)) != NULL)
+    {
+      /* dotfile (or directory) */
+      if (dllconf->d_name[0] == '.')
+        continue;
+
+      len = strlen (dllconf->d_name);
+
+      /* backup files */
+      if ((dllconf->d_name[len-1] == '~')
+          || (dllconf->d_name[len-1] == '#'))
+        continue;
+
+      snprintf (conffile, PATH_MAX, "%s/dll.d/%s",
+                STRINGIFY (PATH_SANE_CONFIG_DIR), dllconf->d_name);
+
+      DBG (5, "sane_init/read_dlld: considering %s\n", conffile);
+
+      if (lstat (conffile, &st) != 0)
+        continue;
+
+      if (!S_ISREG (st.st_mode))
+        continue;
+
+      /* expects a path relative to PATH_SANE_CONFIG_DIR */
+      read_config (conffile+plen);
+    }
+
+  closedir (dlld);
+
+  DBG (5, "sane_init/read_dlld: done.\n");
+}
+
 SANE_Status
 sane_init (SANE_Int * version_code, SANE_Auth_Callback authorize)
 {
 #ifndef __BEOS__
   char config_line[PATH_MAX];
-  char *backend_name;
   size_t len;
   FILE *fp;
   int i;
@@ -762,42 +865,12 @@ sane_init (SANE_Int * version_code, SANE_Auth_Callback authorize)
     *version_code = SANE_VERSION_CODE (SANE_DLL_V_MAJOR, SANE_DLL_V_MINOR,
 				       SANE_DLL_V_BUILD);
 
-  fp = sanei_config_open (DLL_CONFIG_FILE);
-  if (!fp)
-    {
-      DBG (1, "sane_init: Couldn't open config file (%s): %s\n",
-	   DLL_CONFIG_FILE, strerror (errno));
-      return SANE_STATUS_GOOD;	/* don't insist on config file */
-    }
-
-  DBG (5, "sane_init: reading %s\n", DLL_CONFIG_FILE);
-  while (sanei_config_read (config_line, sizeof (config_line), fp))
-    {
-      char *comment;
-      SANE_String_Const cp;
-
-      cp = sanei_config_get_string (config_line, &backend_name);
-      /* ignore empty lines */
-      if (!backend_name || cp == config_line)
-	{
-	  if (backend_name)
-	    free (backend_name);
-	  continue;
-	}
-      /* ignore line comments */
-      if (backend_name[0] == '#')
-	{
-	  free (backend_name);
-	  continue;
-	}
-      /* ignore comments after backend names */
-      comment = strchr (backend_name, '#');
-      if (comment)
-	*comment = '\0';
-      add_backend (backend_name, 0);
-      free (backend_name);
-    }
-  fclose (fp);
+  /*
+   * Read dll.conf & dll.d
+   * Read dll.d first, so that the extras backends will be tried last
+   */
+  read_dlld ();
+  read_config (DLL_CONFIG_FILE);
 
   fp = sanei_config_open (DLL_ALIASES_FILE);
   if (!fp)