From efcddcdd2f58c7a83db77cbe102555331db6656e Mon Sep 17 00:00:00 2001
From: Yorick van Pelt <yorick@yorickvanpelt.nl>
Date: Thu, 27 Jul 2023 13:11:25 +0200
Subject: [PATCH] nix_api_external: fix missing void* self param

---
 src/libexpr/nix_api_external.cc | 4 ++--
 src/libexpr/nix_api_external.h  | 9 ++++++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/libexpr/nix_api_external.cc b/src/libexpr/nix_api_external.cc
index 971a175fb..5fe0819f4 100644
--- a/src/libexpr/nix_api_external.cc
+++ b/src/libexpr/nix_api_external.cc
@@ -139,7 +139,7 @@ public:
     }
     nix_string_context ctx{context};
     std::unique_ptr<nix_returned_string> r(
-        desc.printValueAsJSON((State *)&state, strict, &ctx, copyToStore));
+        desc.printValueAsJSON(v, (State *)&state, strict, &ctx, copyToStore));
     if (!r) {
       return nix::ExternalValueBase::printValueAsJSON(state, strict, context,
                                                       copyToStore);
@@ -160,7 +160,7 @@ public:
           state, strict, location, doc, context, drvsSeen, pos);
     }
     nix_string_context ctx{context};
-    desc.printValueAsXML((State *)&state, strict, location, &doc, &ctx,
+    desc.printValueAsXML(v, (State *)&state, strict, location, &doc, &ctx,
                          &drvsSeen, *reinterpret_cast<const uint32_t *>(&pos));
   }
 
diff --git a/src/libexpr/nix_api_external.h b/src/libexpr/nix_api_external.h
index 2bb53e349..66d289bac 100644
--- a/src/libexpr/nix_api_external.h
+++ b/src/libexpr/nix_api_external.h
@@ -132,6 +132,7 @@ typedef struct NixCExternalValueDesc {
    * @brief Convert the external value to json
    *
    * Optional, the default is to throw an error
+   * @param[in] self the void* passed to nix_create_external_value
    * @param[in] state The evaluator state
    * @param[in] strict boolean Whether to force the value before printing
    * @param[out] c writable string context for the resulting string
@@ -140,7 +141,7 @@ typedef struct NixCExternalValueDesc {
    * @returns string that gets parsed as json. Optional, returning NULL will
    * make the conversion throw an error.
    */
-  nix_returned_string *(*printValueAsJSON)(State *, int strict,
+  nix_returned_string *(*printValueAsJSON)(void *self, State *, int strict,
                                            nix_string_context *c,
                                            bool copyToStore);
   /**
@@ -149,6 +150,7 @@ typedef struct NixCExternalValueDesc {
    * Optional, the default is to throw an error
    * @todo The mechanisms for this call are incomplete. There are no C
    *       bindings to work with XML, pathsets and positions.
+   * @param[in] self the void* passed to nix_create_external_value
    * @param[in] state The evaluator state
    * @param[in] strict boolean Whether to force the value before printing
    * @param[in] location boolean Whether to include position information in the
@@ -158,8 +160,9 @@ typedef struct NixCExternalValueDesc {
    * @param[in,out] drvsSeen a path set to avoid duplicating derivations
    * @param[in] pos The position of the call.
    */
-  void (*printValueAsXML)(State *, int strict, int location, void *doc,
-                          nix_string_context *c, void *drvsSeen, int pos);
+  void (*printValueAsXML)(void *self, State *, int strict, int location,
+                          void *doc, nix_string_context *c, void *drvsSeen,
+                          int pos);
 } NixCExternalValueDesc;
 
 /**