This patch adds the `MergeConfig` and `MergeInConfig` functions to
enable reading new configuration files via a merge strategy rather
than replace. For example, take the following as the base YAML for a
configuration:
hello:
pop: 37890
world:
- us
- uk
- fr
- de
Now imagine we want to read the following, new configuration data:
hello:
pop: 45000
universe:
- mw
- ad
fu: bar
Using the standard `ReadConfig` function the value returned by the
nested key `hello.world` would no longer be present after the second
configuration is read. This is because the `ReadConfig` function and
its relatives replace nested structures entirely.
The new `MergeConfig` function would produce the following config
after the second YAML snippet was merged with the first:
hello:
pop: 45000
world:
- us
- uk
- fr
- de
universe:
- mw
- ad
fu: bar
Examples showing how this works can be found in the two unit tests
named `TestMergeConfig` and `TestMergeConfigNoMerge`.
This reverts commit 8d9577a72e.
The commit is reasonable enough, but this is a major breaking change for Hugo.
We have to figure out how to handle this before we introduce this one.
See https://github.com/spf13/hugo/issues/1129
This fixes the aliases in config files bug. Whenever we register an alias, if there is a value in
the config (or defaults or override) for the alias, we move that value to the new "real key".
Added a test for the bug, which fails without the changes and passes with the changes.
This also fixes a bug in Hugo, where specifying "Taxonomies" in your config file doesn't get recognized,
because Hugo aliases "Taxonomies" to "Indexes" which means that when the code does a Get("Taxnomies") it
got translated to Get("Indexes"), which didn't exist in the original config map.