Include more information in the baton passed around during a merge. No
functional change; this is a step in preparation for detecting whether a
directory to be deleted is the same as what existed in the merge-left
source.

During a merge, pass around in the merge baton the repository location of
the merge sources, instead of just the URL of the merge-right source, so
that the information is available to all callbacks. (Some of the callbacks
already receive some of this information through the svn_diff_callbacks3_t
interface, but inconsistently and incompletely. This change is a local
alternative to revving the callbacks API and making it consistent.)

* subversion/libsvn_client/merge.c
  (merge_source_t): Move this definition to earlier in the file.
  (merge_cmd_baton_t): Replace the "url" field with a "merge_source" field.
  (merge_file_added, merge_dir_added): Adjust usage accordingly.
  (do_merge): Initialise the "merge_source" field instead of the "url" field.

Index: subversion/libsvn_client/merge.c
===================================================================
--- subversion/libsvn_client/merge.c	(revision 32478)
+++ subversion/libsvn_client/merge.c	(working copy)
@@ -192,6 +192,18 @@
 
 /*** Repos-Diff Editor Callbacks ***/
 
+typedef struct merge_source_t
+{
+  /* "left" side URL and revision (inclusive iff youngest) */
+  const char *url1;
+  svn_revnum_t rev1;
+
+  /* "right" side URL and revision (inclusive iff youngest) */
+  const char *url2;
+  svn_revnum_t rev2;
+
+} merge_source_t;
+
 typedef struct merge_cmd_baton_t {
   svn_boolean_t force;
   svn_boolean_t dry_run;
@@ -215,7 +227,7 @@
                                          dir is added as a child of a
                                          versioned dir (dry-run only) */
   const char *target;                 /* Working copy target of merge */
-  const char *url;                    /* The second URL in the merge */
+  merge_source_t merge_source;        /* The left and right URLs and revs */
   svn_client_ctx_t *ctx;              /* Client context for callbacks, etc. */
 
   /* Whether invocation of the merge_file_added() callback required
@@ -884,10 +896,10 @@
                 const char *child = svn_path_is_child(merge_b->target,
                                                       mine, subpool);
                 if (child != NULL)
-                  copyfrom_url = svn_path_url_add_component(merge_b->url,
+                  copyfrom_url = svn_path_url_add_component(merge_b->merge_source.url2,
                                                             child, subpool);
                 else
-                  copyfrom_url = merge_b->url;
+                  copyfrom_url = merge_b->merge_source.url2;
                 copyfrom_rev = rev2;
                 SVN_ERR(check_scheme_match(adm_access, copyfrom_url));
               }
@@ -1152,7 +1164,8 @@
      add. */
   if (merge_b->same_repos)
     {
-      copyfrom_url = svn_path_url_add_component(merge_b->url, child, subpool);
+      copyfrom_url = svn_path_url_add_component(merge_b->merge_source.url2,
+                                                child, subpool);
       copyfrom_rev = rev;
       SVN_ERR(check_scheme_match(adm_access, copyfrom_url));
     }
@@ -4060,18 +4073,6 @@
 
 /*** Merge Source Normalization ***/
 
-typedef struct merge_source_t
-{
-  /* "left" side URL and revision (inclusive iff youngest) */
-  const char *url1;
-  svn_revnum_t rev1;
-
-  /* "right" side URL and revision (inclusive iff youngest) */
-  const char *url2;
-  svn_revnum_t rev2;
-
-} merge_source_t;
-
 /* qsort-compatible sort routine, rating merge_source_t * objects to
    be in descending (youngest-to-oldest) order based on their ->rev1
    component. */
@@ -5514,7 +5515,7 @@
 
       /* Populate the portions of the merge context baton that need to
          be reset for each merge source iteration. */
-      merge_cmd_baton.url = url2;
+      merge_cmd_baton.merge_source = *merge_source;
       merge_cmd_baton.added_path = NULL;
       merge_cmd_baton.add_necessitated_merge = FALSE;
       merge_cmd_baton.dry_run_deletions =