initialized = 1;
		for_each_ref(get_name);
------------

1.   It is preceded by a "git diff" header, that looks like
     this (when the `-c` option is used):

       diff --combined file
+
or like this (when the `--cc` option is used):

       diff --cc file

2.   It is followed by one or more extended header lines
     (this example shows a merge with two parents):
+
[synopsis]
index <hash>,<hash>..<hash>
mode <mode>,<mode>`..`<mode>
new file mode <mode>
deleted file mode <mode>,<mode>
+
The `mode <mode>,<mode>..<mode>` line appears only if at least one of
the <mode> is different from the rest. Extended headers with
information about detected content movement (renames and
copying detection) are designed to work with the diff of two
_<tree-ish>_ and are not used by combined diff format.

3.   It is followed by a two-line from-file/to-file header:

       --- a/file
       +++ b/file
+
Similar to the two-line header for the traditional 'unified' diff
format, `/dev/null` is used to signal created or deleted
files.
+
However, if the --combined-all-paths option is provided, instead of a
two-line from-file/to-file, you get an N+1 line from-file/to-file header,
where N is the number of parents in the merge commit:

       --- a/file
       --- a/file
       --- a/file
       +++ b/file
+
This extended format can be useful if rename or copy detection is
active, to allow you to see the original name of the file in different
parents.

4.   Chunk header format is modified to prevent people from
     accidentally feeding it to `patch -p1`. Combined diff format
     was created for review of merge commit changes, and was not
     meant to be applied. The change is similar to the change in the
     extended 'index' header:

       @@@ <from-file-range> <from-file-range> <to-file-range> @@@
+
There are (number of parents + 1) `@` characters in the chunk
header for combined diff format.

Unlike the traditional 'unified' diff format, which shows two
files A and B with a single column that has `-` (minus --
appears in A but removed in B), `+` (plus -- missing in A but
added to B), or `" "` (space -- unchanged) prefix, this format
compares two or more files file1, file2,... with one file X, and
shows how X differs from each of fileN.  One column for each of
fileN is prepended to the output line to note how X's line is
different from it.

A `-` character in the column N means that the line appears in
fileN but it does not appear in the result.  A `+` character
in the column N means that the line appears in the result,
and fileN does not have that line (in other words, the line was
added, from the point of view of that parent).

In the above example output, the function signature was changed
from both files (hence two `-` removals from both file1 and
file2, plus `++` to mean one line that was added does not appear
in either file1 or file2).  Also, eight other lines are the same
from file1 but do not appear in file2 (hence prefixed with `+`).

When shown by `git diff-tree -c`, it compares the parents of a
merge commit with the merge result (i.e. file1..fileN are the
parents).  When shown by `git diff-files -c`, it compares the
two unresolved merge parents with the working tree file
(i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka
"their version").