libdpkg: On configuration error print file name and line number

debian/changelog

@@ -41,6 +41,7 @@ dpkg (1.15.4) UNRELEASED; urgency=low
     in-tree builds.
   * Use po4a “--previous” support when updating the man pages.
     Suggested by Christian Perrier <bubulle@debian.org>.
+  * On configuration error print file name and line number.
 
   [ Raphael Hertzog ]
   * Replace install-info by a wrapper around GNU's install-info. The wrapper

lib/dpkg/myopt.c

@@ -49,7 +49,7 @@ badusage(const char *fmt, ...)
 }
 
 static void
-config_error(const char *fmt, ...)
+config_error(const char *file_name, int line_num, const char *fmt, ...)
 {
   char buf[1024];
   va_list al;
@@ -58,11 +58,12 @@ config_error(const char *fmt, ...)
   vsnprintf(buf, sizeof(buf), fmt, al);
   va_end(al);
 
-  ohshit(_("configuration error: %s"), buf);
+  ohshit(_("configuration error: %s:%d: %s"), file_name, line_num, buf);
 }
 
 void myfileopt(const char* fn, const struct cmdinfo* cmdinfos) {
   FILE* file;
+  int line_num = 0;
   char linebuf[MAX_CONFIG_LINE];
 
   file= fopen(fn, "r");
@@ -79,6 +80,8 @@ void myfileopt(const char* fn, const struct cmdinfo* cmdinfos) {
     const struct cmdinfo *cip;
     int l;
 
+    line_num++;
+
     if ((linebuf[0] == '#') || (linebuf[0] == '\n') || (linebuf[0] == '\0'))
       continue;
     l=strlen(linebuf);
@@ -106,17 +109,17 @@ void myfileopt(const char* fn, const struct cmdinfo* cmdinfos) {
     }
 
     if (!cip->olong)
-      config_error(_("unknown option '%s'"), linebuf);
+      config_error(fn, line_num, _("unknown option '%s'"), linebuf);
 
     if (cip->takesvalue) {
       if (!opt)
-        config_error(_("'%s' needs a value"), linebuf);
+        config_error(fn, line_num, _("'%s' needs a value"), linebuf);
       if (cip->call) cip->call(cip,opt);
       else
         *cip->sassignto = m_strdup(opt);
     } else {
       if (opt)
-        config_error(_("'%s' does not take a value"), linebuf);
+        config_error(fn, line_num, _("'%s' does not take a value"), linebuf);
       if (cip->call) cip->call(cip,NULL);
       else *cip->iassignto= cip->arg;
     }