Sync with 'master'

Author: gitster

Documentation/RelNotes/2.51.0.adoc

@@ -18,6 +18,8 @@ UI, Workflows & Features
    pathspec at the end of the command line, just like normal "git
    diff".
 
+ * "git subtree" (in contrib/) learned to grok GPG signing its commits.
+
 
 Performance, Internal Implementation, Development Support etc.
 --------------------------------------------------------------
@@ -32,6 +34,9 @@ Performance, Internal Implementation, Development Support etc.
  * Meson-based build/test framework now understands TAP output
    generated by our tests.
 
+ * "Do not explicitly initialize to zero" rule has been clarified in
+   the CodingGuidelines document.
+
 
 Fixes since v2.50
 -----------------
@@ -47,6 +52,23 @@ Fixes since v2.50
    corrected.
    (merge 3717a5775a jw/doc-txt-to-adoc-refs later to maint).
 
+ * "git stash -p <pathspec>" improvements.
+   (merge 468817bab2 pw/stash-p-pathspec-fixes later to maint).
+
+ * "git send-email" incremented its internal message counter when a
+   message was edited, which made logic that treats the first message
+   specially misbehave, which has been corrected.
+   (merge 2cc27b3501 ag/send-email-edit-threading-fix later to maint).
+
+ * "git stash" recorded a wrong branch name when submodules are
+   present in the current checkout, which has been corrected.
+   (merge ffb36c64f2 kj/stash-onbranch-submodule-fix later to maint).
+
+ * When asking to apply mailmap to both author and committer field
+   while showing a commit object, the field that appears later was not
+   correctly parsed and replaced, which has been corrected.
+   (merge abf94a283f sa/multi-mailmap-fix later to maint).
+
  * Other code cleanup, docfix, build fix, etc.
    (merge b257adb571 lo/my-first-ow-doc-update later to maint).
    (merge 8b34b6a220 ly/sequencer-update-squash-is-fixup-only later to maint).
@@ -56,3 +78,7 @@ Fixes since v2.50
    (merge bfc9f9cc64 ly/submodule-update-failure-leakfix later to maint).
    (merge 65dff89c6b ma/doc-diff-cc-headers later to maint).
    (merge efb61591ee jm/bundle-uri-debug-output-to-fp later to maint).
+   (merge a3d278bb64 ly/prepare-show-merge-leakfix later to maint).
+   (merge 1fde1c5daf ac/preload-index-wo-the-repository later to maint).
+   (merge 855cfc65ae rm/t2400-modernize later to maint).
+   (merge 2939494284 ly/run-builtin-use-passed-in-repo later to maint).