this when the branches to be merged have diverged wildly.
See also linkgit:git-diff[1] `--patience`.
+diff-algorithm=[patience|minimal|histogram|myers];;
+ Tells 'merge-recursive' to use a different diff algorithm, which
+ can help avoid mismerges that occur due to unimportant matching
+ lines (such as braces from distinct functions). See also
+ linkgit:git-diff[1] `--diff-algorithm`.
+
ignore-space-change;;
ignore-all-space;;
ignore-space-at-eol;;
match the tree structure of A, instead of reading the trees at
the same level. This adjustment is also done to the common
ancestor tree.
+
+With the strategies that use 3-way merge (including the default, 'recursive'),
+if a change is made on both branches, but later reverted on one of the
+branches, that change will be present in the merged result; some people find
+this behavior confusing. It occurs because only the heads and the merge base
+are considered when performing a merge, not the individual commits. The merge
+algorithm therefore considers the reverted change as no change at all, and
+substitutes the changed version instead.