[PATCH v2 0/9] diff --color-moved-ws fixes and enhancment

From: Phillip Wood <phillip.wood@dunelm.org.uk>

Thanks to Stefan for his feedback on v1. I've updated patches 2 & 8 in response to those comments - see the range-diff below for details (the patch numbers are off by one in the range diff, I think because the first patch is unchanged and so it was used as the merge base by --range-diff=<old-head>. For some reason the range-diff also includes the notes even though I did not give --notes to format-patch)

When trying out the new --color-moved-ws=allow-indentation-change I was disappointed to discover it did not work if the indentation contains a mix of spaces and tabs. This series reworks it so that it does.

Phillip Wood (9):
  diff: document --no-color-moved
  Use "whitespace" consistently
  diff: allow --no-color-moved-ws
  diff --color-moved-ws: demonstrate false positives
  diff --color-moved-ws: fix false positives
  diff --color-moved=zebra: be stricter with color alternation
  diff --color-moved-ws: optimize allow-indentation-change
  diff --color-moved-ws: modify allow-indentation-change
  diff --color-moved-ws: handle blank lines

 Documentation/diff-options.txt |  15 ++-
 Documentation/git-cat-file.txt |   8 +-
 diff.c                         | 219 +++++++++++++++++++++------------
 t/t4015-diff-whitespace.sh     |  99 ++++++++++++++-
 4 files changed, 255 insertions(+), 86 deletions(-)

Range-diff against v1:
1:  ae58ae4f29 ! 1:  4939ee371d diff: use whitespace consistently
    @@ -1,9 +1,10 @@
     Author: Phillip Wood <phillip.wood@dunelm.org.uk>
     
    -    diff: use whitespace consistently
    +    Use "whitespace" consistently
     
    -    Most of the documentation uses 'whitespace' rather than 'white space'
    -    or 'white spaces' convert to latter two to the former for consistency.
    +    Most of the messages and documentation use 'whitespace' rather than
    +    'white space' or 'white spaces' convert to latter two to the former for
    +    consistency.
     
         Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
     
    @@ -29,6 +30,39 @@
      	whitespace is the same per line. This is incompatible with the
      	other modes.
     
    + diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt
    + --- a/Documentation/git-cat-file.txt
    + +++ b/Documentation/git-cat-file.txt
    +@@
    + stdin, and the SHA-1, type, and size of each object is printed on stdout. The
    + output format can be overridden using the optional `<format>` argument. If
    + either `--textconv` or `--filters` was specified, the input is expected to
    +-list the object names followed by the path name, separated by a single white
    +-space, so that the appropriate drivers can be determined.
    ++list the object names followed by the path name, separated by a single
    ++whitespace, so that the appropriate drivers can be determined.
    + 
    + OPTIONS
    + -------
    +@@
    + 	Print object information and contents for each object provided
    + 	on stdin.  May not be combined with any other options or arguments
    + 	except `--textconv` or `--filters`, in which case the input lines
    +-	also need to specify the path, separated by white space.  See the
    ++	also need to specify the path, separated by whitespace.  See the
    + 	section `BATCH OUTPUT` below for details.
    + 
    + --batch-check::
    + --batch-check=<format>::
    + 	Print object information for each object provided on stdin.  May
    + 	not be combined with any other options or arguments except
    + 	`--textconv` or `--filters`, in which case the input lines also
    +-	need to specify the path, separated by white space.  See the
    ++	need to specify the path, separated by whitespace.  See the
    + 	section `BATCH OUTPUT` below for details.
    + 
    + --batch-all-objects::
    +
      diff --git a/diff.c b/diff.c
      --- a/diff.c
      +++ b/diff.c
2:  7072bc6211 = 2:  204c7fea9d diff: allow --no-color-moved-ws
3:  ce3ad19eea = 3:  542b79b215 diff --color-moved-ws: demonstrate false positives
4:  700e0b61e7 = 4:  4ffb5c4122 diff --color-moved-ws: fix false positives
5:  9ecd8159a7 = 5:  a3a84f90c5 diff --color-moved=zebra: be stricter with color alternation
6:  1b1158b1ca = 6:  f94f2e0bae diff --color-moved-ws: optimize allow-indentation-change
7:  d8a362be6a ! 7:  fe8eb9cdbc diff --color-moved-ws: modify allow-indentation-change
    @@ -17,7 +17,7 @@
     
         This commit changes the way the indentation is handled to track the
         visual size of the indentation rather than the characters in the
    -    indentation. This has they benefit that any whitespace errors do not
    +    indentation. This has the benefit that any whitespace errors do not
         interfer with the move detection (the whitespace errors will still be
         highlighted according to --ws-error-highlight). During the discussion
         of this feature there were concerns about the correct detection of
    @@ -30,7 +30,7 @@
             they are uncolored.
     
         Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
    -    Changes since rfc:
    +    changes since rfc:
          - It now replaces the existing implementation rather than adding a new
            mode.
          - The indentation deltas are now calculated once for each line and
    @@ -49,8 +49,8 @@
      	const char *line;
      	int len;
      	int flags;
    -+	int indent_off;
    -+	int indent_width;
    ++	int indent_off;   /* Offset to first non-whitespace character */
    ++	int indent_width; /* The visual width of the indentation */
      	enum diff_symbol s;
      };
      #define EMITTED_DIFF_SYMBOL_INIT {NULL}
8:  1f7e99d45c = 8:  e600f8247c diff --color-moved-ws: handle blank lines