patch 8.1.0360: using an external diff program is slow and inflexible
Problem: Using an external diff program is slow and inflexible.
Solution: Include the xdiff library. (Christian Brabandt, closes #2732)
Use it by default.
diff --git a/runtime/doc/diff.txt b/runtime/doc/diff.txt
index d56aea7..6670f45 100644
--- a/runtime/doc/diff.txt
+++ b/runtime/doc/diff.txt
@@ -39,7 +39,9 @@
then append the file name of the first argument to the directory name to find
the file.
-This only works when a standard "diff" command is available. See 'diffexpr'.
+By default an internal diff library will be used. When 'diffopt' or
+'diffexpr' has been set an external "diff" command will be used. This only
+works when such a diff program is available.
Diffs are local to the current tab page |tab-page|. You can't see diffs with
a window in another tab page. This does make it possible to have several
@@ -344,8 +346,9 @@
The ">" is replaced with the value of 'shellredir'.
-The output of "diff" must be a normal "ed" style diff. Do NOT use a context
-diff. This example explains the format that Vim expects: >
+The output of "diff" must be a normal "ed" style diff or a unified diff. Do
+NOT use a context diff. This example explains the format that Vim expects for
+the "ed" style diff: >
1a2
> bbb