The function to detect a BOM takes an offset where it shall look for a BOM. No caller uses that, and searching for the BOM in the middle of a buffer seems to be very unlikely, as a BOM should only ever exist at file start. Remove the parameter, as it has already caused confusion due to its weirdness.
Next to including several files, our "common.h" header also declares various macros which are then used throughout the project. As such, we have to make sure to always include this file first in all implementation files. Otherwise, we might encounter problems or even silent behavioural differences due to macros or defines not being defined as they should be. So in fact, our header and implementation files should make sure to always include "common.h" first. This commit does so by establishing a common include pattern. Header files inside of "src" will now always include "common.h" as its first other file, separated by a newline from all the other includes to make it stand out as special. There are two cases for the implementation files. If they do have a matching header file, they will always include this one first, leading to "common.h" being transitively included as first file. If they do not have a matching header file, they instead include "common.h" as first file themselves. This fixes the outlined problems and will become our standard practice for header and source files inside of the "src/" from now on.
Allow files to have mixed line endings instead of skipping processing on them.
When checking out files, we're performing conversion into the user's native line endings, but we only want to do it for files which have consistent line endings. Refuse to perform the conversion for mixed-EOL files. The CRLF->LF filter is left as-is, as that conversion is considered to be normalization by git and should force a conversion of the line endings.
This begins the process of exposing git_filter objects to the public API. This includes: * new public type and API for `git_buffer` through which an allocated buffer can be passed to the user * new API `git_blob_filtered_content` * make the git_filter type and GIT_FILTER_TO_... constants public
This adds crlf/lf conversion functions into buf_text with more efficient implementations that bypass the high level buffer functions. They attempt to minimize the number of reallocations done and they directly write the buffer data as needed if they know that there is enough memory allocated to memcpy data. Tests are added for these new functions. The crlf.c code is updated to use the new functions. Removed the include of buf_text.h from filter.h and just include it more narrowly in the places that need it.
Core git just looks for NUL bytes in files when deciding about is-binary inside diff (although it uses a better algorithm in checkout, when deciding if CRLF conversion should be done). Libgit2 was using the better algorithm in both places, but that is causing some confusion. For now, this makes diff just look for NUL bytes to decide if a file is binary by content in diff.
There are many scattered functions that look into the contents of buffers to do various text manipulations (such as escaping or unescaping data, calculating text stats, guessing if content is binary, etc). This groups all those functions together into a new file and converts the code to use that. This has two enhancements to existing functionality. The old text stats function is significantly rewritten and the BOM detection code was extended (although largely we can't deal with anything other than a UTF8 BOM).