Log message:
[[[
Allow case-only renames on case-insensitive filesystems (issue #3702).

* subversion/svn/move-cmd.c
  (svn_cl__move): If the targets are paths, and there are exactly two, and
   the normalized DST_PATH and SRC_PATH are equal, canonicalize the original
   DST_PATH again, but without converting it to on-disk casing.

* subversion/libsvn_client/copy.c
  (do_wc_to_wc_moves_with_locks2): Pass TRUE for keep_local when calling
   svn_wc_delete4 after just having performed the svn_io_file_rename. Because
   it has just been renamed, the src_abspath_or_url should already be gone.
   This avoids deleting the destination in case of a case-only rename.
  (verify_wc_srcs_and_dsts): When the dst_abspath_or_url already exists,
   see if its "truepath" (matching path on the filesystem, module case) is
   the same as the src_abspath_or_url, to account for a possible case-only
   rename. In that case, don't complain about that the dst already exists.
]]]
Index: subversion/svn/move-cmd.c
===================================================================
--- subversion/svn/move-cmd.c   (revision 1092816)
+++ subversion/svn/move-cmd.c   (working copy)
@@ -30,6 +30,7 @@
 #include "svn_client.h"
 #include "svn_error.h"
 #include "svn_path.h"
+#include "svn_utf.h"
 #include "cl.h"

 #include "svn_private_config.h"
@@ -76,6 +77,27 @@ svn_cl__move(apr_getopt_t *os,
           (SVN_ERR_CL_UNNECESSARY_LOG_MESSAGE, NULL,
            _("Local, non-commit operations do not take a log message "
              "or revision properties"));
+
+      /* For allowing case-only renames on Windows (issue #3702):
+         If DST_PATH is a path, and there is exactly one source path, check if
+         the normalized DST_PATH and SRC_PATH are equal. If so, canonicalize
+         the original DST_PATH again, but without converting it to on-disk
+         casing, so we can pass the intended destination to
+         svn_client_move6. */
+      if (targets->nelts == 1)
+        {
+          const char *src_path = APR_ARRAY_IDX(targets, targets->nelts - 1,
+                                               const char *);
+
+          if (strcmp(src_path, dst_path) == 0)
+            {
+              const char *utf8_target;
+
+              SVN_ERR(svn_utf_cstring_to_utf8(&utf8_target,
+                                              os->argv[os->argc - 1], pool));
+              dst_path = svn_dirent_canonicalize(utf8_target, pool);
+            }
+        }
     }

   if (ctx->log_msg_func3)
Index: subversion/libsvn_client/copy.c
===================================================================
--- subversion/libsvn_client/copy.c     (revision 1092816)
+++ subversion/libsvn_client/copy.c     (working copy)
@@ -347,8 +347,14 @@ do_wc_to_wc_moves_with_locks2(void *baton,
   SVN_ERR(svn_io_file_rename(b->pair->src_abspath_or_url, dst_abspath,
                              scratch_pool));

+  /* ### JC: Deleting with keep_local==TRUE should be fine, because the above
+     rename should have already (re)moved src_abspath_or_url, so it should no
+     longer be present on the filesystem. Without keep_local, a case-only
+     rename on a case-insensitive filesystem doesn't work: the dst of the
+     rename is deleted here (because it's equal to the src, modulo case). */
   SVN_ERR(svn_wc_delete4(b->ctx->wc_ctx, b->pair->src_abspath_or_url,
-                         FALSE, FALSE,
+                         TRUE /* keep_local */,
+                         FALSE /* delete_unversioned_target */,
                          b->ctx->cancel_func, b->ctx->cancel_baton,
                          b->ctx->notify_func2, b->ctx->notify_baton2,
                          scratch_pool));
@@ -482,11 +488,46 @@ verify_wc_srcs_and_dsts(const apr_array_header_t *
       SVN_ERR(svn_io_check_path(pair->dst_abspath_or_url, &dst_kind,
                                 iterpool));
       if (dst_kind != svn_node_none)
-        return svn_error_createf(
-          SVN_ERR_ENTRY_EXISTS, NULL,
-          _("Path '%s' already exists"),
-          svn_dirent_local_style(pair->dst_abspath_or_url, pool));
+        {
+          /* ### JC: Get the dst's truepath, just in case we passed a
+             non-truepath dst for doing a case-only rename, so we can check
+             here if we're doing a case-only rename (which shouldn't be
+             blocked here). This code is mainly copy-pasted from
+             libsvn_subr/opt.c#svn_opt__arg_canonicalize_path - should
+             probably end up somewhere else ... */
+          const char *apr_target;
+          const char *dst_truepath;
+          const char *dst_truepath_utf8;
+          apr_status_t apr_err;
+
+          SVN_ERR(svn_path_cstring_from_utf8(&apr_target,
+                                             pair->dst_abspath_or_url,
+                                             iterpool));
+          apr_err = apr_filepath_merge(&dst_truepath, "", apr_target,
+                                       APR_FILEPATH_TRUENAME, iterpool);
+          /* convert back to UTF-8. */
+          SVN_ERR(svn_path_cstring_to_utf8(&dst_truepath_utf8,
+                                           dst_truepath, iterpool));
+          dst_truepath_utf8 = svn_dirent_canonicalize(dst_truepath_utf8,
+                                                      iterpool);

+          if (dst_kind == pair->src_kind
+              && strcmp(pair->src_abspath_or_url,
+                        dst_truepath_utf8) == 0
+              && strcmp(pair->src_abspath_or_url,
+                        pair->dst_abspath_or_url) != 0)
+            {
+              /* It's a case-only rename, just let it go through */
+            }
+          else
+            {
+              return svn_error_createf(
+                SVN_ERR_ENTRY_EXISTS, NULL,
+                _("Path '%s' already exists"),
+                svn_dirent_local_style(pair->dst_abspath_or_url, pool));
+            }
+        }
+
       svn_dirent_split(&pair->dst_parent_abspath, &pair->base_name,
                        pair->dst_abspath_or_url, pool);