doc: clarify that --word-diff operates on line-level hunks

From: Michael Montalbo <[email protected]>

The --word-diff documentation describes the output modes and word-regex mechanics but does not explain that word-diff operates within the hunks produced by the line-level diff rather than performing an independent word-stream comparison. This can surprise users when the line-level alignment causes word-level changes to appear even though the words in both files are identical.

Add a short note explaining the two-stage relationship.

---
doc: clarify that --word-diff operates on line-level hunks

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2113%2Fmmontalbo%2Fmm%2Fdoc-word-diff-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2113/mmontalbo/mm/doc-word-diff-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/2113

 Documentation/diff-options.adoc | 5 +++++
 1 file changed, 5 insertions(+)

index 8a63b5e164..665473e61a 100644
@@ -457,6 +457,11 @@ endif::git-diff[]
 +
 Note that despite the name of the first mode, color is used to
 highlight the changed parts in all modes if enabled.
++
+Word diff works by finding word-level changes within each hunk of
+the line-level diff.  The line-level alignment determines which
+changed lines are compared to each other, which can affect the
+word-level output.
 
 `--word-diff-regex=<regex>`::
 	Use _<regex>_ to decide what a word is, instead of considering

base-commit: 94f057755b7941b321fd11fec1b2e3ca5313a4e0

gitgitgadget

From: Michael Montalbo <[email protected]>

The --word-diff documentation describes the output modes and word-regex mechanics but does not explain that word-diff operates within the hunks produced by the line-level diff rather than performing an independent word-stream comparison. This can surprise users when the line-level alignment causes word-level changes to appear even though the words in both files are identical.

Add an implementation note explaining the two-stage relationship and that the output may change if Git acquires a different implementation in the future.

---
doc: clarify that --word-diff operates on line-level hunks

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2113%2Fmmontalbo%2Fmm%2Fdoc-word-diff-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2113/mmontalbo/mm/doc-word-diff-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/2113

Range-diff vs v1:

1: 73f7b06c06 ! 1: bc5ca5a147 doc: clarify that --word-diff operates on line-level hunks
@@ Commit message
changes to appear even though the words in both files are identical.

- Add a short note explaining the two-stage relationship.
+ Add an implementation note explaining the two-stage relationship
+ and that the output may change if Git acquires a different
+ implementation in the future.

@@ Documentation/diff-options.adoc: endif::git-diff[]
Note that despite the name of the first mode, color is used to highlight the changed parts in all modes if enabled.
++
-+Word diff works by finding word-level changes within each hunk of -+the line-level diff. The line-level alignment determines which -+changed lines are compared to each other, which can affect the -+word-level output.
++The --word-diff option operates by taking the same line-by-line ++diff that is produced without the option and computing ++word-by-word changes within each hunk. This may produce a ++larger diff than a dedicated word-diff tool would. If Git ++acquires a different implementation in the future, the output ++may change. Note that this is similar to the --diff-algorithm ++option, which may also change the output.

--word-diff-regex=<regex>::
Use _<regex>_ to decide what a word is, instead of considering

 Documentation/diff-options.adoc | 8 ++++++++
 1 file changed, 8 insertions(+)

index 8a63b5e164..c8242e2462 100644
@@ -457,6 +457,14 @@ endif::git-diff[]
 +
 Note that despite the name of the first mode, color is used to
 highlight the changed parts in all modes if enabled.
++
+The `--word-diff` option operates by taking the same line-by-line
+diff that is produced without the option and computing
+word-by-word changes within each hunk.  This may produce a
+larger diff than a dedicated word-diff tool would.  If Git
+acquires a different implementation in the future, the output
+may change.  Note that this is similar to the `--diff-algorithm`
+option, which may also change the output.
 
 `--word-diff-regex=<regex>`::
 	Use _<regex>_ to decide what a word is, instead of considering

base-commit: 94f057755b7941b321fd11fec1b2e3ca5313a4e0

gitgitgadget