pandoc: Add patches for nixpkgs docs

Until we update pandoc, these are necessary for faithful Markdown to Docbook conversion in the manual.
The following features are necessary for many pages, in particular the GNOME platform docs:

* Anchors should use `xml:id` attribute, as mandated by Docbook 5.
* Admonitions should be supported, including titles.

Additionally, xmlns should be set correctly for root element.

1 files changed, 25 insertions, 1 deletions

diff --git a/pkgs/development/tools/pandoc/default.nix b/pkgs/development/tools/pandoc/default.nix
index 0bf9ce71e48..dbee7631fe0 100644
--- a/pkgs/development/tools/pandoc/default.nix
+++ b/pkgs/development/tools/pandoc/default.nix
@@ -1,4 +1,4 @@
-{ haskellPackages, haskell, removeReferencesTo }:
+{ haskellPackages, fetchpatch, haskell, removeReferencesTo }:
 
 let
   static = haskell.lib.justStaticExecutables haskellPackages.pandoc;
@@ -8,6 +8,30 @@ in
     configureFlags = drv.configureFlags or [] ++ ["-fembed_data_files"];
     buildDepends = drv.buildDepends or [] ++ [haskellPackages.file-embed];
     buildTools = (drv.buildTools or []) ++ [ removeReferencesTo ];
+    patches = (drv.patches or []) ++ [
+      # Add xmlns to top-level tags in Docbook, required for nixpkgs manual.
+      # https://github.com/jgm/pandoc/pull/6923
+      (fetchpatch {
+        url = "https://github.com/jgm/pandoc/commit/6f35600204132c5a0907bb7cccb2e10ffb27506a.patch";
+        sha256 = "gRUqc4YG4lZdCZn21fPmlcrFyZ3/VlDx71lU8GMuGSs=";
+      })
+      # Generate admonitions in DocBook, required for nixpkgs manual.
+      # https://github.com/jgm/pandoc/pull/6922
+      (fetchpatch {
+        url = "https://github.com/jgm/pandoc/commit/dc6856530c2cb6ca58ed82721ab895b86cfe0c1c.patch";
+        sha256 = "EdsUDlHzsfRscXBR4EP2Z5ZEz+NfrmFHnV7c1hJczio=";
+      })
+      # Use correct id attributes in DocBook, required for nixpkgs manual.
+      (fetchpatch {
+        url = "https://github.com/jgm/pandoc/commit/16ef87745702f69d5aa948fbe6d2101577dee8f4.patch";
+        sha256 = "WyWTqrO6hGsMgJ7o7QL1BNvhkm0yIO1XJOcfPBDy6ag=";
+      })
+      # Allow using admonition titles from Markdown in DocBook.
+      (fetchpatch {
+        url = "https://github.com/jgm/pandoc/commit/70c7c5703afcbd1cbf2a80c2be515e038abcd419.patch";
+        sha256 = "2kHQ1qy/UdDi/chwCBvMjAPA/XFH42vWFCjR46Jgt6M=";
+      })
+    ];
   })).overrideAttrs (drv: {
 
     # These libraries are still referenced, because they generate