Document -B<n>[/<m>], -M<n> and -C<n> variants of -B, -M and -C
These options take an optional argument, but this optional argument was not documented. Original patch by Matthieu Moy, but documentation for -B mostly copied from the explanations of Junio C Hamano. While we're there, fix a typo in a comment in diffcore.h. Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Matthieu Moy committed
Aug 5, 2010 at 18:14 UTC
cf958afd8368ebce1cabb2f7ae2799306cc2de03
2 files changed
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Documentation/diff-options.txt
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@@ -206,10 +206,29 @@ endif::git-format-patch[]
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the diff-patch output format. Non default number of
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digits can be specified with `--abbrev=<n>`.
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--B::
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- Break complete rewrite changes into pairs of delete and create.
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-
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--M::
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+-B[<n>][/<m>]::
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+ Break complete rewrite changes into pairs of delete and
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+ create. This serves two purposes:
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++
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+It affects the way a change that amounts to a total rewrite of a file
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+not as a series of deletion and insertion mixed together with a very
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+few lines that happen to match textually as the context, but as a
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+single deletion of everything old followed by a single insertion of
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+everything new, and the number `m` controls this aspect of the -B
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+option (defaults to 60%). `-B/70%` specifies that less than 30% of the
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+original should remain in the result for git to consider it a total
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+rewrite (i.e. otherwise the resulting patch will be a series of
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+deletion and insertion mixed together with context lines).
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++
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+When used with -M, a totally-rewritten file is also considered as the
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+source of a rename (usually -M only considers a file that disappeared
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+as the source of a rename), and the number `n` controls this aspect of
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+the -B option (defaults to 50%). `-B20%` specifies that a change with
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+addition and deletion compared to 20% or more of the file's size are
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+eligible for being picked up as a possible source of a rename to
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+another file.
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+
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+-M[<n>]::
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ifndef::git-log[]
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Detect renames.
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endif::git-log[]
@@ -218,9 +237,15 @@ ifdef::git-log[]
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For following files across renames while traversing history, see
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`--follow`.
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endif::git-log[]
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+ If `n` is specified, it is a is a threshold on the similarity
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+ index (i.e. amount of addition/deletions compared to the
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+ file's size). For example, `-M90%` means git should consider a
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+ delete/add pair to be a rename if more than 90% of the file
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+ hasn't changed.
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--C::
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+-C[<n>]::
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Detect copies as well as renames. See also `--find-copies-harder`.
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+ If `n` is specified, it has the same meaning as for `-M<n>`.
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ifndef::git-format-patch[]
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--diff-filter=[ACDMRTUXB*]::
diffcore.h
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@@ -18,7 +18,7 @@
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#define MAX_SCORE 60000.0
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#define DEFAULT_RENAME_SCORE 30000 /* rename/copy similarity minimum (50%) */
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#define DEFAULT_BREAK_SCORE 30000 /* minimum for break to happen (50%) */
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-#define DEFAULT_MERGE_SCORE 36000 /* maximum for break-merge to happen 60%) */
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+#define DEFAULT_MERGE_SCORE 36000 /* maximum for break-merge to happen (60%) */
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#define MINIMUM_BREAK_SIZE 400 /* do not break a file smaller than this */
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