Add support for patch files renaming dirs to files and files to dirs

doc/index.html

@@ -82,6 +82,8 @@ <h1>opam %{OPAMVERSION}% API and libraries documentation</h1>
   <td>Parallel execution of jobs following a directed graph</td></tr>
 <tr><th><a href="opam-core/OpamUrl">opamUrl.ml</a></th>
   <td>URL parsing and printing, with support for our different backends</td></tr>
+<tr><th><a href="opam-core/OpamPatch">opamPatch.ml</a></th>
+  <td>Patch application, translation and parsing</td></tr>
 
 <tr><td colspan="2" class="sublib">Windows support</td></tr>
 <tr><th><a href="opam-core/OpamStubs">opamStubs.ml</a></th>

master_changes.md

@@ -53,6 +53,7 @@ users)
   * Compute the list of available depexts on `opam update` [#6489 @arozovyk - fix #6461]
   * Update depexts availability repository state cache when running `opam update --depexts` [#6489 @arozovyk - fix #6461]
   * Display status message while loading system package availability during `opam update` [#6489 @arozovyk - fix #6461]
+  * `opam update` now supports updating a repository that changed a file to a directory of the same name and vice versa [#6915 @rjbou @arozovyk - fix #3830]
 
 ## Tree
 
@@ -145,6 +146,9 @@ users)
 ## Internal: Windows
 
 ## Test
+  * lib/patchDiff: no longer print unecessary information after patch [#6915 @rjbou]
+  * lib/patchDiff: Ensure a more consistent output accross Unix and Windows platforms [#6915 @kit-ty-kate]
+  * lib/patchdiff: add dir-file transformations tests [#6915 @rjbou]
 
 ## Benchmarks
   * Add an even larger real-world diff to benchmark `opam update` [#6567 @kit-ty-kate]
@@ -161,6 +165,7 @@ users)
   * Add a test showing the behaviour of .install files containing destination filepath trying to escape their scope [#6897 @rjbou @kit-ty-kate]
   * Add a test showing that `opam install ./` will leave packages pinned if
     aborted or failed [#6922 @NathanReb]
+  * Add test for update in repository that changes directories to files and vice versa [#6915 @rjbou]
 
 ### Engine
 
@@ -247,6 +252,8 @@ users)
   * `OpamCompat.MAP.filter_map`: was removed [#6879 @kit-ty-kate]
   * `OpamCompat.Map.add_to_list`: was added [#6818 @dra27]
   * `OpamSystem`: add `is_dir_read_only` [#6489 @rjbou]
+  * `OpamSystem.*patch` were moved to `OpamPatch` [#6915 @rjbou]
   * `OpamFilename`: add `is_dir_read_only` [#6489 @rjbou]
   * `OpamFilename.might_escape`: ensure / is detected as a file separator when called with `~sep:Unspecified` on Windows [#6897 @kit-ty-kate]
   * `OpamFilename.Unix` was added abstracting over `/` separated paths regardless of the current system [#6914 @rjbou @kit-ty-kate]
+  * `OpamPatch` was added [#6915 @rjbou]

src/core/opamFilename.ml

@@ -456,14 +456,14 @@ let link ?(relative=false) ~target ~link =
 [@@ocaml.warning "-16"]
 
 let parse_patch ~dir patch_file =
-  OpamSystem.parse_patch ~dir:(Dir.to_string dir) ~file:(to_string patch_file)
+  OpamPatch.parse_patch ~dir:(Dir.to_string dir) ~file:(to_string patch_file)
 
 let patch ~allow_unclean patch_source dir =
   let operations_result diffs =
     Ok (List.map (fun d -> d.Patch.operation) diffs)
   in
   let patch ?patch_filename diffs =
-    OpamSystem.patch ~allow_unclean ?patch_filename ~dir:(Dir.to_string dir)
+    OpamPatch.patch ~allow_unclean ?patch_filename ~dir:(Dir.to_string dir)
       diffs
   in
   try