src/crlf.c - third_party/libgit2 - Git at Google

 /*
  * Copyright (C) the libgit2 contributors. All rights reserved.
  *
  * This file is part of libgit2, distributed under the GNU GPL v2 with
  * a Linking Exception. For full terms see the included COPYING file.
  */

 #include "git2/attr.h"
 #include "git2/blob.h"
 #include "git2/index.h"
 #include "git2/sys/filter.h"

 #include "common.h"
 #include "fileops.h"
 #include "hash.h"
 #include "filter.h"
 #include "buf_text.h"
 #include "repository.h"

 struct crlf_attrs {
 	int crlf_action;
 	int eol;
 	int auto_crlf;
 	int safe_crlf;
 };

 struct crlf_filter {
 	git_filter f;
 };

 static int check_crlf(const char *value)
 {
 	if (GIT_ATTR_TRUE(value))
 		return GIT_CRLF_TEXT;

 	if (GIT_ATTR_FALSE(value))
 		return GIT_CRLF_BINARY;

 	if (GIT_ATTR_UNSPECIFIED(value))
 		return GIT_CRLF_GUESS;

 	if (strcmp(value, "input") == 0)
 		return GIT_CRLF_INPUT;

 	if (strcmp(value, "auto") == 0)
 		return GIT_CRLF_AUTO;

 	return GIT_CRLF_GUESS;
 }

 static int check_eol(const char *value)
 {
 	if (GIT_ATTR_UNSPECIFIED(value))
 		return GIT_EOL_UNSET;

 	if (strcmp(value, "lf") == 0)
 		return GIT_EOL_LF;

 	if (strcmp(value, "crlf") == 0)
 		return GIT_EOL_CRLF;

 	return GIT_EOL_UNSET;
 }

 static int crlf_input_action(struct crlf_attrs *ca)
 {
 	if (ca->crlf_action == GIT_CRLF_BINARY)
 		return GIT_CRLF_BINARY;

 	if (ca->eol == GIT_EOL_LF)
 		return GIT_CRLF_INPUT;

 	if (ca->eol == GIT_EOL_CRLF)
 		return GIT_CRLF_CRLF;

 	return ca->crlf_action;
 }

 static int has_cr_in_index(const git_filter_source *src)
 {
 	git_repository *repo = git_filter_source_repo(src);
 	const char *path = git_filter_source_path(src);
 	git_index *index;
 	const git_index_entry *entry;
 	git_blob *blob;
 	const void *blobcontent;
 	git_off_t blobsize;
 	bool found_cr;

 	if (!path)
 		return false;

 	if (git_repository_index__weakptr(&index, repo) < 0) {
 		giterr_clear();
 		return false;
 	}

 	if (!(entry = git_index_get_bypath(index, path, 0)) &&
 		!(entry = git_index_get_bypath(index, path, 1)))
 		return false;

 	if (!S_ISREG(entry->mode)) /* don't crlf filter non-blobs */
 		return true;

 	if (git_blob_lookup(&blob, repo, &entry->id) < 0)
 		return false;

 	blobcontent = git_blob_rawcontent(blob);
 	blobsize    = git_blob_rawsize(blob);
 	if (!git__is_sizet(blobsize))
 		blobsize = (size_t)-1;

 	found_cr = (blobcontent != NULL &&
 		blobsize > 0 &&
 		memchr(blobcontent, '\r', (size_t)blobsize) != NULL);

 	git_blob_free(blob);
 	return found_cr;
 }

 static int crlf_apply_to_odb(
 	struct crlf_attrs *ca,
 	git_buf *to,
 	const git_buf *from,
 	const git_filter_source *src)
 {
 	/* Empty file? Nothing to do */
 	if (!git_buf_len(from))
 		return 0;

 	/* Heuristics to see if we can skip the conversion.
 	 * Straight from Core Git.
 	 */
 	if (ca->crlf_action == GIT_CRLF_AUTO || ca->crlf_action == GIT_CRLF_GUESS) {
 		git_buf_text_stats stats;

 		/* Check heuristics for binary vs text - returns true if binary */
 		if (git_buf_text_gather_stats(&stats, from, false))
 			return GIT_PASSTHROUGH;

 		/* If there are no CR characters to filter out, then just pass */
 		if (!stats.cr)
 			return GIT_PASSTHROUGH;

 		/* If safecrlf is enabled, sanity-check the result. */
 		if (stats.cr != stats.crlf || stats.lf != stats.crlf) {
 			switch (ca->safe_crlf) {
 			case GIT_SAFE_CRLF_FAIL:
 				giterr_set(
 					GITERR_FILTER, "LF would be replaced by CRLF in '%s'",
 					git_filter_source_path(src));
 				return -1;
 			case GIT_SAFE_CRLF_WARN:
 				/* TODO: issue warning when warning API is available */;
 				break;
 			default:
 				break;
 			}
 		}

 		/*
 		 * We're currently not going to even try to convert stuff
 		 * that has bare CR characters. Does anybody do that crazy
 		 * stuff?
 		 */
 		if (stats.cr != stats.crlf)
 			return GIT_PASSTHROUGH;

 		if (ca->crlf_action == GIT_CRLF_GUESS) {
 			/*
 			 * If the file in the index has any CR in it, do not convert.
 			 * This is the new safer autocrlf handling.
 			 */
 			if (has_cr_in_index(src))
 				return GIT_PASSTHROUGH;
 		}

 		if (!stats.cr)
 			return GIT_PASSTHROUGH;
 	}

 	/* Actually drop the carriage returns */
 	return git_buf_text_crlf_to_lf(to, from);
 }

 static const char *line_ending(struct crlf_attrs *ca)
 {
 	switch (ca->crlf_action) {
 	case GIT_CRLF_BINARY:
 	case GIT_CRLF_INPUT:
 		return "\n";

 	case GIT_CRLF_CRLF:
 		return "\r\n";

 	case GIT_CRLF_GUESS:
 		if (ca->auto_crlf == GIT_AUTO_CRLF_FALSE)
 			return "\n";
 		break;

 	case GIT_CRLF_AUTO:
 	case GIT_CRLF_TEXT:
 		break;

 	default:
 		goto line_ending_error;
 	}

 	if (ca->auto_crlf == GIT_AUTO_CRLF_TRUE)
 		return "\r\n";
 	else if (ca->auto_crlf == GIT_AUTO_CRLF_INPUT)
 		return "\n";
 	else if (ca->eol == GIT_EOL_UNSET)
 		return GIT_EOL_NATIVE == GIT_EOL_CRLF ? "\r\n" : "\n";
 	else if (ca->eol == GIT_EOL_LF)
 		return "\n";
 	else if (ca->eol == GIT_EOL_CRLF)
 		return "\r\n";

 line_ending_error:
 	giterr_set(GITERR_INVALID, "Invalid input to line ending filter");
 	return NULL;
 }

 static int crlf_apply_to_workdir(
 	struct crlf_attrs *ca, git_buf *to, const git_buf *from)
 {
 	git_buf_text_stats stats;
 	const char *workdir_ending = NULL;
 	bool is_binary;

 	/* Empty file? Nothing to do. */
 	if (git_buf_len(from) == 0)
 		return 0;

 	/* Determine proper line ending */
 	workdir_ending = line_ending(ca);
 	if (!workdir_ending)
 		return -1;

 	/* only LF->CRLF conversion is supported, do nothing on LF platforms */
 	if (strcmp(workdir_ending, "\r\n") != 0)
 		return GIT_PASSTHROUGH;

 	/* If there are no LFs, or all LFs are part of a CRLF, nothing to do */
 	is_binary = git_buf_text_gather_stats(&stats, from, false);

 	if (stats.lf == 0 || stats.lf == stats.crlf)
 		return GIT_PASSTHROUGH;

 	if (ca->crlf_action == GIT_CRLF_AUTO ||
 		ca->crlf_action == GIT_CRLF_GUESS) {

 		/* If we have any existing CR or CRLF line endings, do nothing */
 		if (ca->crlf_action == GIT_CRLF_GUESS &&
 			stats.cr > 0 && stats.crlf > 0)
 			return GIT_PASSTHROUGH;

 		/* If we have bare CR characters, do nothing */
 		if (stats.cr != stats.crlf)
 			return GIT_PASSTHROUGH;

 		/* Don't filter binary files */
 		if (is_binary)
 			return GIT_PASSTHROUGH;
 	}

 	return git_buf_text_lf_to_crlf(to, from);
 }

 static int crlf_check(
 	git_filter        *self,
 	void              **payload, /* points to NULL ptr on entry, may be set */
 	const git_filter_source *src,
 	const char **attr_values)
 {
 	int error;
 	struct crlf_attrs ca;

 	GIT_UNUSED(self);

 	if (!attr_values) {
 		ca.crlf_action = GIT_CRLF_GUESS;
 		ca.eol = GIT_EOL_UNSET;
 	} else {
 		ca.crlf_action = check_crlf(attr_values[2]); /* text */
 		if (ca.crlf_action == GIT_CRLF_GUESS)
 			ca.crlf_action = check_crlf(attr_values[0]); /* clrf */
 		ca.eol = check_eol(attr_values[1]); /* eol */
 	}
 	ca.auto_crlf = GIT_AUTO_CRLF_DEFAULT;
 	ca.safe_crlf = GIT_SAFE_CRLF_DEFAULT;

 	/*
 	 * Use the core Git logic to see if we should perform CRLF for this file
 	 * based on its attributes & the value of `core.autocrlf`
 	 */
 	ca.crlf_action = crlf_input_action(&ca);

 	if (ca.crlf_action == GIT_CRLF_BINARY)
 		return GIT_PASSTHROUGH;

 	if (ca.crlf_action == GIT_CRLF_GUESS ||
 		((ca.crlf_action == GIT_CRLF_AUTO || ca.crlf_action == GIT_CRLF_TEXT) &&
 		git_filter_source_mode(src) == GIT_FILTER_SMUDGE)) {

 		error = git_repository__cvar(
 			&ca.auto_crlf, git_filter_source_repo(src), GIT_CVAR_AUTO_CRLF);
 		if (error < 0)
 			return error;

 		if (ca.crlf_action == GIT_CRLF_GUESS &&
 			ca.auto_crlf == GIT_AUTO_CRLF_FALSE)
 			return GIT_PASSTHROUGH;

 		if (ca.auto_crlf == GIT_AUTO_CRLF_INPUT &&
 			git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
 			return GIT_PASSTHROUGH;
 	}

 	if (git_filter_source_mode(src) == GIT_FILTER_CLEAN) {
 		error = git_repository__cvar(
 			&ca.safe_crlf, git_filter_source_repo(src), GIT_CVAR_SAFE_CRLF);
 		if (error < 0)
 			return error;

 		/* downgrade FAIL to WARN if ALLOW_UNSAFE option is used */
 		if ((git_filter_source_flags(src) & GIT_FILTER_ALLOW_UNSAFE) &&
 			ca.safe_crlf == GIT_SAFE_CRLF_FAIL)
 			ca.safe_crlf = GIT_SAFE_CRLF_WARN;
 	}

 	*payload = git__malloc(sizeof(ca));
 	GITERR_CHECK_ALLOC(*payload);
 	memcpy(*payload, &ca, sizeof(ca));

 	return 0;
 }

 static int crlf_apply(
 	git_filter    *self,
 	void         **payload, /* may be read and/or set */
 	git_buf       *to,
 	const git_buf *from,
 	const git_filter_source *src)
 {
 	/* initialize payload in case `check` was bypassed */
 	if (!*payload) {
 		int error = crlf_check(self, payload, src, NULL);
 		if (error < 0)
 			return error;
 	}

 	if (git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
 		return crlf_apply_to_workdir(*payload, to, from);
 	else
 		return crlf_apply_to_odb(*payload, to, from, src);
 }

 static void crlf_cleanup(
 	git_filter *self,
 	void       *payload)
 {
 	GIT_UNUSED(self);
 	git__free(payload);
 }

 git_filter *git_crlf_filter_new(void)
 {
 	struct crlf_filter *f = git__calloc(1, sizeof(struct crlf_filter));
 	if (f == NULL)
 		return NULL;

 	f->f.version = GIT_FILTER_VERSION;
 	f->f.attributes = "crlf eol text";
 	f->f.initialize = NULL;
 	f->f.shutdown = git_filter_free;
 	f->f.check    = crlf_check;
 	f->f.apply    = crlf_apply;
 	f->f.cleanup  = crlf_cleanup;

 	return (git_filter *)f;
 }
	/*
	* Copyright (C) the libgit2 contributors. All rights reserved.
	*
	* This file is part of libgit2, distributed under the GNU GPL v2 with
	* a Linking Exception. For full terms see the included COPYING file.
	*/

	#include "git2/attr.h"
	#include "git2/blob.h"
	#include "git2/index.h"
	#include "git2/sys/filter.h"

	#include "common.h"
	#include "fileops.h"
	#include "hash.h"
	#include "filter.h"
	#include "buf_text.h"
	#include "repository.h"

	struct crlf_attrs {
	int crlf_action;
	int eol;
	int auto_crlf;
	int safe_crlf;
	};

	struct crlf_filter {
	git_filter f;
	};

	static int check_crlf(const char *value)
	{
	if (GIT_ATTR_TRUE(value))
	return GIT_CRLF_TEXT;

	if (GIT_ATTR_FALSE(value))
	return GIT_CRLF_BINARY;

	if (GIT_ATTR_UNSPECIFIED(value))
	return GIT_CRLF_GUESS;

	if (strcmp(value, "input") == 0)
	return GIT_CRLF_INPUT;

	if (strcmp(value, "auto") == 0)
	return GIT_CRLF_AUTO;

	return GIT_CRLF_GUESS;
	}

	static int check_eol(const char *value)
	{
	if (GIT_ATTR_UNSPECIFIED(value))
	return GIT_EOL_UNSET;

	if (strcmp(value, "lf") == 0)
	return GIT_EOL_LF;

	if (strcmp(value, "crlf") == 0)
	return GIT_EOL_CRLF;

	return GIT_EOL_UNSET;
	}

	static int crlf_input_action(struct crlf_attrs *ca)
	{
	if (ca->crlf_action == GIT_CRLF_BINARY)
	return GIT_CRLF_BINARY;

	if (ca->eol == GIT_EOL_LF)
	return GIT_CRLF_INPUT;

	if (ca->eol == GIT_EOL_CRLF)
	return GIT_CRLF_CRLF;

	return ca->crlf_action;
	}

	static int has_cr_in_index(const git_filter_source *src)
	{
	git_repository *repo = git_filter_source_repo(src);
	const char *path = git_filter_source_path(src);
	git_index *index;
	const git_index_entry *entry;
	git_blob *blob;
	const void *blobcontent;
	git_off_t blobsize;
	bool found_cr;

	if (!path)
	return false;

	if (git_repository_index__weakptr(&index, repo) < 0) {
	giterr_clear();
	return false;
	}

	if (!(entry = git_index_get_bypath(index, path, 0)) &&
	!(entry = git_index_get_bypath(index, path, 1)))
	return false;

	if (!S_ISREG(entry->mode)) /* don't crlf filter non-blobs */
	return true;

	if (git_blob_lookup(&blob, repo, &entry->id) < 0)
	return false;

	blobcontent = git_blob_rawcontent(blob);
	blobsize = git_blob_rawsize(blob);
	if (!git__is_sizet(blobsize))
	blobsize = (size_t)-1;

	found_cr = (blobcontent != NULL &&
	blobsize > 0 &&
	memchr(blobcontent, '\r', (size_t)blobsize) != NULL);

	git_blob_free(blob);
	return found_cr;
	}

	static int crlf_apply_to_odb(
	struct crlf_attrs *ca,
	git_buf *to,
	const git_buf *from,
	const git_filter_source *src)
	{
	/* Empty file? Nothing to do */
	if (!git_buf_len(from))
	return 0;

	/* Heuristics to see if we can skip the conversion.
	* Straight from Core Git.
	*/
	if (ca->crlf_action == GIT_CRLF_AUTO \|\| ca->crlf_action == GIT_CRLF_GUESS) {
	git_buf_text_stats stats;

	/* Check heuristics for binary vs text - returns true if binary */
	if (git_buf_text_gather_stats(&stats, from, false))
	return GIT_PASSTHROUGH;

	/* If there are no CR characters to filter out, then just pass */
	if (!stats.cr)
	return GIT_PASSTHROUGH;

	/* If safecrlf is enabled, sanity-check the result. */
	if (stats.cr != stats.crlf \|\| stats.lf != stats.crlf) {
	switch (ca->safe_crlf) {
	case GIT_SAFE_CRLF_FAIL:
	giterr_set(
	GITERR_FILTER, "LF would be replaced by CRLF in '%s'",
	git_filter_source_path(src));
	return -1;
	case GIT_SAFE_CRLF_WARN:
	/* TODO: issue warning when warning API is available */;
	break;
	default:
	break;
	}
	}

	/*
	* We're currently not going to even try to convert stuff
	* that has bare CR characters. Does anybody do that crazy
	* stuff?
	*/
	if (stats.cr != stats.crlf)
	return GIT_PASSTHROUGH;

	if (ca->crlf_action == GIT_CRLF_GUESS) {
	/*
	* If the file in the index has any CR in it, do not convert.
	* This is the new safer autocrlf handling.
	*/
	if (has_cr_in_index(src))
	return GIT_PASSTHROUGH;
	}

	if (!stats.cr)
	return GIT_PASSTHROUGH;
	}

	/* Actually drop the carriage returns */
	return git_buf_text_crlf_to_lf(to, from);
	}

	static const char line_ending(struct crlf_attrs ca)
	{
	switch (ca->crlf_action) {
	case GIT_CRLF_BINARY:
	case GIT_CRLF_INPUT:
	return "\n";

	case GIT_CRLF_CRLF:
	return "\r\n";

	case GIT_CRLF_GUESS:
	if (ca->auto_crlf == GIT_AUTO_CRLF_FALSE)
	return "\n";
	break;

	case GIT_CRLF_AUTO:
	case GIT_CRLF_TEXT:
	break;

	default:
	goto line_ending_error;
	}

	if (ca->auto_crlf == GIT_AUTO_CRLF_TRUE)
	return "\r\n";
	else if (ca->auto_crlf == GIT_AUTO_CRLF_INPUT)
	return "\n";
	else if (ca->eol == GIT_EOL_UNSET)
	return GIT_EOL_NATIVE == GIT_EOL_CRLF ? "\r\n" : "\n";
	else if (ca->eol == GIT_EOL_LF)
	return "\n";
	else if (ca->eol == GIT_EOL_CRLF)
	return "\r\n";

	line_ending_error:
	giterr_set(GITERR_INVALID, "Invalid input to line ending filter");
	return NULL;
	}

	static int crlf_apply_to_workdir(
	struct crlf_attrs ca, git_buf to, const git_buf *from)
	{
	git_buf_text_stats stats;
	const char *workdir_ending = NULL;
	bool is_binary;

	/* Empty file? Nothing to do. */
	if (git_buf_len(from) == 0)
	return 0;

	/* Determine proper line ending */
	workdir_ending = line_ending(ca);
	if (!workdir_ending)
	return -1;

	/* only LF->CRLF conversion is supported, do nothing on LF platforms */
	if (strcmp(workdir_ending, "\r\n") != 0)
	return GIT_PASSTHROUGH;

	/* If there are no LFs, or all LFs are part of a CRLF, nothing to do */
	is_binary = git_buf_text_gather_stats(&stats, from, false);

	if (stats.lf == 0 \|\| stats.lf == stats.crlf)
	return GIT_PASSTHROUGH;

	if (ca->crlf_action == GIT_CRLF_AUTO \|\|
	ca->crlf_action == GIT_CRLF_GUESS) {

	/* If we have any existing CR or CRLF line endings, do nothing */
	if (ca->crlf_action == GIT_CRLF_GUESS &&
	stats.cr > 0 && stats.crlf > 0)
	return GIT_PASSTHROUGH;

	/* If we have bare CR characters, do nothing */
	if (stats.cr != stats.crlf)
	return GIT_PASSTHROUGH;

	/* Don't filter binary files */
	if (is_binary)
	return GIT_PASSTHROUGH;
	}

	return git_buf_text_lf_to_crlf(to, from);
	}

	static int crlf_check(
	git_filter *self,
	void *payload, / points to NULL ptr on entry, may be set */
	const git_filter_source *src,
	const char **attr_values)
	{
	int error;
	struct crlf_attrs ca;

	GIT_UNUSED(self);

	if (!attr_values) {
	ca.crlf_action = GIT_CRLF_GUESS;
	ca.eol = GIT_EOL_UNSET;
	} else {
	ca.crlf_action = check_crlf(attr_values[2]); /* text */
	if (ca.crlf_action == GIT_CRLF_GUESS)
	ca.crlf_action = check_crlf(attr_values[0]); /* clrf */
	ca.eol = check_eol(attr_values[1]); /* eol */
	}
	ca.auto_crlf = GIT_AUTO_CRLF_DEFAULT;
	ca.safe_crlf = GIT_SAFE_CRLF_DEFAULT;

	/*
	* Use the core Git logic to see if we should perform CRLF for this file
	* based on its attributes & the value of `core.autocrlf`
	*/
	ca.crlf_action = crlf_input_action(&ca);

	if (ca.crlf_action == GIT_CRLF_BINARY)
	return GIT_PASSTHROUGH;

	if (ca.crlf_action == GIT_CRLF_GUESS \|\|
	((ca.crlf_action == GIT_CRLF_AUTO \|\| ca.crlf_action == GIT_CRLF_TEXT) &&
	git_filter_source_mode(src) == GIT_FILTER_SMUDGE)) {

	error = git_repository__cvar(
	&ca.auto_crlf, git_filter_source_repo(src), GIT_CVAR_AUTO_CRLF);
	if (error < 0)
	return error;

	if (ca.crlf_action == GIT_CRLF_GUESS &&
	ca.auto_crlf == GIT_AUTO_CRLF_FALSE)
	return GIT_PASSTHROUGH;

	if (ca.auto_crlf == GIT_AUTO_CRLF_INPUT &&
	git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
	return GIT_PASSTHROUGH;
	}

	if (git_filter_source_mode(src) == GIT_FILTER_CLEAN) {
	error = git_repository__cvar(
	&ca.safe_crlf, git_filter_source_repo(src), GIT_CVAR_SAFE_CRLF);
	if (error < 0)
	return error;

	/* downgrade FAIL to WARN if ALLOW_UNSAFE option is used */
	if ((git_filter_source_flags(src) & GIT_FILTER_ALLOW_UNSAFE) &&
	ca.safe_crlf == GIT_SAFE_CRLF_FAIL)
	ca.safe_crlf = GIT_SAFE_CRLF_WARN;
	}

	*payload = git__malloc(sizeof(ca));
	GITERR_CHECK_ALLOC(*payload);
	memcpy(*payload, &ca, sizeof(ca));

	return 0;
	}

	static int crlf_apply(
	git_filter *self,
	void *payload, / may be read and/or set */
	git_buf *to,
	const git_buf *from,
	const git_filter_source *src)
	{
	/* initialize payload in case `check` was bypassed */
	if (!*payload) {
	int error = crlf_check(self, payload, src, NULL);
	if (error < 0)
	return error;
	}

	if (git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
	return crlf_apply_to_workdir(*payload, to, from);
	else
	return crlf_apply_to_odb(*payload, to, from, src);
	}

	static void crlf_cleanup(
	git_filter *self,
	void *payload)
	{
	GIT_UNUSED(self);
	git__free(payload);
	}

	git_filter *git_crlf_filter_new(void)
	{
	struct crlf_filter *f = git__calloc(1, sizeof(struct crlf_filter));
	if (f == NULL)
	return NULL;

	f->f.version = GIT_FILTER_VERSION;
	f->f.attributes = "crlf eol text";
	f->f.initialize = NULL;
	f->f.shutdown = git_filter_free;
	f->f.check = crlf_check;
	f->f.apply = crlf_apply;
	f->f.cleanup = crlf_cleanup;

	return (git_filter *)f;
	}