[patch] Load plugins based on VDRVERSION and APIVERSION alternatively

[udo_richter at gmx.de (Udo Richter)]

Hi Klaus,


The new APIVERSION of 1.3.47 will cause lots of trouble as soon as 
APIVERSION and VDRVERSION differ the first time, as this requires 
updated Makefiles for all plugins. In best case, VDR wont find a plugin 
because it has the wrong name, in worst case, an old version is used 
without noticing.

On the other hand, its not too difficult to load plugins based on 
APIVERSION and VDRVERSION alternatively. That way, plugins that still 
use VDRVERSION continue to work. This even gives plugin authors the 
ability to ignore APIVERSION compatibility if the plugin depends on 
obscure differences between versions. The only drawback is that plugin 
authors will be lazy adapting to APIVERSION.

The attached patch does the trick: It loads plugins using APIVERSION and 
VDRVERSION, and gives VDRVERSION the precedence. The patch also prefers 
VDRVERSION when loading "*". Feel free to use it if you want.

Cheers,

Udo
-------------- next part --------------
--- vdr-1.3.47-orig/plugin.c	2006-04-21 19:08:02.000000000 +0200
+++ vdr-1.3.47/plugin.c	2006-04-21 19:53:32.709327912 +0200
@@ -294,11 +294,26 @@
               if (p) {
                  *p = 0;
                  p += strlen(SO_INDICATOR);
-                 if (strcmp(p, APIVERSION) == 0) {
+                 if (strcmp(p, VDRVERSION) == 0) {
+                    // VDRVERSION is always loaded
                     char *name = e->d_name + strlen(LIBVDR_PREFIX);
                     if (strcmp(name, "*") != 0) { // let's not get into a loop!
-                       AddPlugin(e->d_name + strlen(LIBVDR_PREFIX));
+                       AddPlugin(name);
+                       }
+                    }
+                 if (strcmp(p, APIVERSION) == 0) {
+                    // APIVERSION found, check whether VDRVERSION exists too
+                    char *name = e->d_name + strlen(LIBVDR_PREFIX);
+                    char *buffer = NULL;
+                    asprintf(&buffer, "%s/%s%s%s%s", directory, LIBVDR_PREFIX, name, SO_INDICATOR, VDRVERSION);
+                    if (access(buffer,F_OK) != 0) {
+                       // APIVERSION is the only existing one, use it
+                       if (strcmp(name, "*") != 0) { // let's not get into a loop!
+                          AddPlugin(name);
+                          }
                        }
+                    // else: skip APIVERSION, the loop will load VDRVERSION instead
+                    free(buffer);
                     }
                  }
               }
@@ -310,7 +325,11 @@
   if (p)
      *p = 0;
   char *buffer = NULL;
-  asprintf(&buffer, "%s/%s%s%s%s", directory, LIBVDR_PREFIX, s, SO_INDICATOR, APIVERSION);
+  asprintf(&buffer, "%s/%s%s%s%s", directory, LIBVDR_PREFIX, s, SO_INDICATOR, VDRVERSION);
+  if (access(buffer,F_OK) != 0) { // Plugin not found using VDRVERSION, try APIVERSION instead
+     free(buffer);
+     asprintf(&buffer, "%s/%s%s%s%s", directory, LIBVDR_PREFIX, s, SO_INDICATOR, APIVERSION);
+     }
   dlls.Add(new cDll(buffer, Args));
   free(buffer);
   free(s);