Documentation: rev-list-options: move --simplify-merges documentation
Fits --simplify-merges documentation into the 'History Simplification' section, including example. Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Thomas Rast committed
Aug 12, 2008 at 01:55 UTC
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Documentation/rev-list-options.txt
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@@ -193,12 +193,6 @@ endif::git-rev-list[]
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Stop when a given path disappears from the tree.
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---simplify-merges::
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-
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- Simplify away commits that did not change the given paths, similar
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- to `--full-history`, and further remove merges none of whose
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- parent history changes the given paths.
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-
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--no-merges::
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Do not print commits with more than one parent.
@@ -413,6 +407,48 @@ Note that without '\--full-history', this still simplifies merges: if
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one of the parents is TREESAME, we follow only that one, so the other
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sides of the merge are never walked.
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+Finally, there is a fourth simplification mode available:
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+
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+--simplify-merges::
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+
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+ First, build a history graph in the same way that
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+ '\--full-history' with parent rewriting does (see above).
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++
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+Then simplify each commit `C` to its replacement `C'` in the final
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+history according to the following rules:
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++
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+--
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+* Set `C'` to `C`.
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++
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+* Replace each parent `P` of `C'` with its simplification `P'`. In
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+ the process, drop parents that are ancestors of other parents, and
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+ remove duplicates.
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++
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+* If after this parent rewriting, `C'` is a root or merge commit (has
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+ zero or >1 parents), a boundary commit, or !TREESAME, it remains.
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+ Otherwise, it is replaced with its only parent.
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+--
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++
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+The effect of this is best shown by way of comparing to
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+'\--full-history' with parent rewriting. The example turns into:
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++
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+-----------------------------------------------------------------------
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+ .-A---M---N---O
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+ / / /
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+ I B D
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+ \ / /
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+ `---------'
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+-----------------------------------------------------------------------
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++
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+Note the major differences in `N` and `P` over '\--full-history':
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++
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+--
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+* `N`'s parent list had `I` removed, because it is an ancestor of the
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+ other parent `M`. Still, `N` remained because it is !TREESAME.
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++
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+* `P`'s parent list similarly had `I` removed. `P` was then
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+ removed completely, because it had one parent and is TREESAME.
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+--
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ifdef::git-rev-list[]
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