* doc/emacs/trouble.texi (Sending Patches):
Fix the typo (bug#23657).
Use @samp{diff -u} to make your diffs. Diffs without context are hard
to install reliably. More than that, they are hard to study; we must
always study a patch to decide whether we want to install it. Context
-format is better than contextless diffs, but we prefer we unified format.
+format is better than contextless diffs, but we prefer the unified
+format.
If you have GNU diff, use @samp{diff -u -F'^[_a-zA-Z0-9$]\+ *('} when
making diffs of C code. This shows the name of the function that each