1 files changed, 31 insertions, 8 deletions

diff --git a/subversion/libsvn_client/ctx.c b/subversion/libsvn_client/ctx.c
index 185b91e..05a5eec 100644
--- a/subversion/libsvn_client/ctx.c
+++ b/subversion/libsvn_client/ctx.c
@@ -27,6 +27,7 @@
 
 /*** Includes. ***/
 
+#include <stddef.h>
 #include <apr_pools.h>
 #include "svn_hash.h"
 #include "svn_client.h"
@@ -34,6 +35,8 @@
 
 #include "private/svn_wc_private.h"
 
+#include "client.h"
+
 
 /*** Code. ***/
 
@@ -76,6 +79,20 @@ call_conflict_func(svn_wc_conflict_result_t **result,
   return SVN_NO_ERROR;
 }
 
+/* The magic number in client_ctx_t.magic_id. */
+#define CLIENT_CTX_MAGIC APR_UINT64_C(0xDEADBEEF600DF00D)
+
+svn_client__private_ctx_t *
+svn_client__get_private_ctx(svn_client_ctx_t *ctx)
+{
+  svn_client__private_ctx_t *const private_ctx =
+    (void*)((char *)ctx - offsetof(svn_client__private_ctx_t, public_ctx));
+  SVN_ERR_ASSERT_NO_RETURN(&private_ctx->public_ctx == ctx);
+  SVN_ERR_ASSERT_NO_RETURN(0 == private_ctx->magic_null);
+  SVN_ERR_ASSERT_NO_RETURN(CLIENT_CTX_MAGIC == private_ctx->magic_id);
+  return private_ctx;
+}
+
 svn_error_t *
 svn_client_create_context2(svn_client_ctx_t **ctx,
                            apr_hash_t *cfg_hash,
@@ -83,23 +100,29 @@ svn_client_create_context2(svn_client_ctx_t **ctx,
 {
   svn_config_t *cfg_config;
 
-  *ctx = apr_pcalloc(pool, sizeof(svn_client_ctx_t));
+  svn_client__private_ctx_t *const private_ctx =
+    apr_pcalloc(pool, sizeof(*private_ctx));
+  svn_client_ctx_t *const public_ctx = &private_ctx->public_ctx;
+
+  private_ctx->magic_null = 0;
+  private_ctx->magic_id = CLIENT_CTX_MAGIC;
 
-  (*ctx)->notify_func2 = call_notify_func;
-  (*ctx)->notify_baton2 = *ctx;
+  public_ctx->notify_func2 = call_notify_func;
+  public_ctx->notify_baton2 = public_ctx;
 
-  (*ctx)->conflict_func2 = call_conflict_func;
-  (*ctx)->conflict_baton2 = *ctx;
+  public_ctx->conflict_func2 = call_conflict_func;
+  public_ctx->conflict_baton2 = public_ctx;
 
-  (*ctx)->config = cfg_hash;
+  public_ctx->config = cfg_hash;
 
   if (cfg_hash)
     cfg_config = svn_hash_gets(cfg_hash, SVN_CONFIG_CATEGORY_CONFIG);
   else
     cfg_config = NULL;
 
-  SVN_ERR(svn_wc_context_create(&(*ctx)->wc_ctx, cfg_config, pool,
-                                pool));
+  SVN_ERR(svn_wc_context_create(&public_ctx->wc_ctx, cfg_config,
+                                pool, pool));
+  *ctx = public_ctx;
 
   return SVN_NO_ERROR;
 }