Print a debug message if a page has multiple source files.

IkiWiki/Render.pm

@@ -279,7 +279,11 @@ sub refresh () { #{{{
 				else {
 					$f=~s/^\Q$config{srcdir}\E\/?//;
 					push @files, $f;
-					$exists{pagename($f)}=1;
+					my $pagename = pagename($f);
+					if ($exists{$pagename}) {
+						debug(sprintf(gettext("%s has multiple possible source pages"), $pagename));
+					}
+					$exists{$pagename}=1;
 				}
 			}
 		},

debian/changelog

@@ -16,6 +16,7 @@ ikiwiki (2.65) UNRELEASED; urgency=low
   * edittemplate: Link to template, to allow creating it. (Willu)
   * editpage: Add a missing check that the page name contains only legal
     characters, in addition to the existing check for pruned filenames.
+  * Print a debug message if a page has multiple source files.
 
  -- Joey Hess <joeyh@debian.org>  Wed, 17 Sep 2008 14:26:56 -0400
 

doc/bugs/multiple_pages_with_same_name.mdwn

@@ -4,6 +4,10 @@ I realised that this is going to have problems when you ask it to process `.c` a
 
 I tested it briefly with `test.java` and `test.mdwn` just to see what would happen.  Things got quite strange.  The source-highlighting plugin was called (probably for the java file), but then when it calls `pagetype($pagesources{$page})` to figure out the file type, that function returns `mdwn`, which confuses things somewhat.
 
+> This is a known possible point of confusion. If there are multiple source
+> files, it will render them both, in an arbitrary sequence, so one "wins".
+> --[[Joey]]
+
 Anyway, I'm thinking about possible solutions.  The best option I've come up with so far is: when registering an htmlize hook, add a new optional paramter 'keep_extension'.  This would make a source file of `hello.c` generate a page with name `hello.c` rather than the current `hello`.  This would keep the pages unique (until someone makes `hello.c.mdwn`...).
 
 Suggestions welcome.
@@ -12,6 +16,11 @@ Suggestions welcome.
 
 > Ok, this turned out not to be a hard change.  [[patch]] is below.  With this patch you can tell IkiWiki not to drop the suffix when you register a hook: `hook(type => "htmlize", id => $lang, call => \&htmlize, leavesuffix => 1);`
 
+>> I think that's a good solution to the problem that most syntax plugins
+>> have struggled with. It makes sense. It doesn't solve the case where
+>> you have source files without any extension (eg `Makefile`), but at
+>> least it covers the common cases.
+
     diff --git a/IkiWiki.pm b/IkiWiki.pm
     index 4e4da11..853f905 100644
     --- a/IkiWiki.pm