git log -S does not show anything

Question

I've used git log -S many times with great success but this time, it does not show anything.
I'm looking for the commit that introduced pagesNum.

Here is what I do:

$ git status
On branch master
nothing to commit, working directory clean
$ git grep pagesNum
resources/locales/en.json:    "search-page": "{pagesNum} Select...",
$ git log -SpagesNum
$ git log -S"pagesNum"
$ git log -S"pagesNum" --all
$

How is it possible that git log does not show anything??

Answer 1

Apparently, -S does not consider text that was introduced in a merge commit.

I just tested this by committing and empty commit, and then merging it, but adding a change. Doing this causes git grep to find the text, but git log -S shows nothing.

As a remedy, try the -m option with git log which considers the diff to all parents, although you will probably also want to add the --first-parent option to only consider the diff to the main parent. However, --first-parent will only show the merge commit that introduced the change, and not the regular commit, if applicable. Unfortunately, there is no way to modify the -m option to show only the first parent without having that option apply to the selection of commits as well.