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-rw-r--r--Documentation/config.txt45
-rw-r--r--Documentation/gitattributes.txt20
-rw-r--r--builtin-apply.c2
-rw-r--r--builtin-blame.c2
-rw-r--r--cache.h11
-rw-r--r--config.c9
-rw-r--r--convert.c47
-rw-r--r--diff.c2
-rw-r--r--environment.c1
-rw-r--r--sha1_file.c3
-rwxr-xr-xt/t0020-crlf.sh58
11 files changed, 189 insertions, 11 deletions
diff --git a/Documentation/config.txt b/Documentation/config.txt
index f9bdb164e0..f2f6a774e0 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -139,6 +139,51 @@ core.autocrlf::
"text" (i.e. be subjected to the autocrlf mechanism) is
decided purely based on the contents.
+core.safecrlf::
+ If true, makes git check if converting `CRLF` as controlled by
+ `core.autocrlf` is reversible. Git will verify if a command
+ modifies a file in the work tree either directly or indirectly.
+ For example, committing a file followed by checking out the
+ same file should yield the original file in the work tree. If
+ this is not the case for the current setting of
+ `core.autocrlf`, git will reject the file. The variable can
+ be set to "warn", in which case git will only warn about an
+ irreversible conversion but continue the operation.
++
+CRLF conversion bears a slight chance of corrupting data.
+autocrlf=true will convert CRLF to LF during commit and LF to
+CRLF during checkout. A file that contains a mixture of LF and
+CRLF before the commit cannot be recreated by git. For text
+files this is the right thing to do: it corrects line endings
+such that we have only LF line endings in the repository.
+But for binary files that are accidentally classified as text the
+conversion can corrupt data.
++
+If you recognize such corruption early you can easily fix it by
+setting the conversion type explicitly in .gitattributes. Right
+after committing you still have the original file in your work
+tree and this file is not yet corrupted. You can explicitly tell
+git that this file is binary and git will handle the file
+appropriately.
++
+Unfortunately, the desired effect of cleaning up text files with
+mixed line endings and the undesired effect of corrupting binary
+files cannot be distinguished. In both cases CRLFs are removed
+in an irreversible way. For text files this is the right thing
+to do because CRLFs are line endings, while for binary files
+converting CRLFs corrupts data.
++
+Note, this safety check does not mean that a checkout will generate a
+file identical to the original file for a different setting of
+`core.autocrlf`, but only for the current one. For example, a text
+file with `LF` would be accepted with `core.autocrlf=input` and could
+later be checked out with `core.autocrlf=true`, in which case the
+resulting file would contain `CRLF`, although the original file
+contained `LF`. However, in both work trees the line endings would be
+consistent, that is either all `LF` or all `CRLF`, but never mixed. A
+file with mixed line endings would be reported by the `core.safecrlf`
+mechanism.
+
core.symlinks::
If false, symbolic links are checked out as small plain files that
contain the link text. linkgit:git-update-index[1] and
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 35a29fd60c..84ec9623a2 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -133,6 +133,26 @@ When `core.autocrlf` is set to "input", line endings are
converted to LF upon checkin, but there is no conversion done
upon checkout.
+If `core.safecrlf` is set to "true" or "warn", git verifies if
+the conversion is reversible for the current setting of
+`core.autocrlf`. For "true", git rejects irreversible
+conversions; for "warn", git only prints a warning but accepts
+an irreversible conversion. The safety triggers to prevent such
+a conversion done to the files in the work tree, but there are a
+few exceptions. Even though...
+
+- "git add" itself does not touch the files in the work tree, the
+ next checkout would, so the safety triggers;
+
+- "git apply" to update a text file with a patch does touch the files
+ in the work tree, but the operation is about text files and CRLF
+ conversion is about fixing the line ending inconsistencies, so the
+ safety does not trigger;
+
+- "git diff" itself does not touch the files in the work tree, it is
+ often run to inspect the changes you intend to next "git add". To
+ catch potential problems early, safety triggers.
+
`ident`
^^^^^^^
diff --git a/builtin-apply.c b/builtin-apply.c
index 46dad5b2a1..6a88ff018d 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -1430,7 +1430,7 @@ static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
case S_IFREG:
if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
return error("unable to open or read %s", path);
- convert_to_git(path, buf->buf, buf->len, buf);
+ convert_to_git(path, buf->buf, buf->len, buf, 0);
return 0;
default:
return -1;
diff --git a/builtin-blame.c b/builtin-blame.c
index c7e68874e7..1cf254dcca 100644
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -2073,7 +2073,7 @@ static struct commit *fake_working_tree_commit(const char *path, const char *con
if (strbuf_read(&buf, 0, 0) < 0)
die("read error %s from stdin", strerror(errno));
}
- convert_to_git(path, buf.buf, buf.len, &buf);
+ convert_to_git(path, buf.buf, buf.len, &buf, 0);
origin->file.ptr = buf.buf;
origin->file.size = buf.len;
pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_sha1);
diff --git a/cache.h b/cache.h
index 18fe8447f3..e1000bccb2 100644
--- a/cache.h
+++ b/cache.h
@@ -383,6 +383,14 @@ extern size_t packed_git_limit;
extern size_t delta_base_cache_limit;
extern int auto_crlf;
+enum safe_crlf {
+ SAFE_CRLF_FALSE = 0,
+ SAFE_CRLF_FAIL = 1,
+ SAFE_CRLF_WARN = 2,
+};
+
+extern enum safe_crlf safe_crlf;
+
#define GIT_REPO_VERSION 0
extern int repository_format_version;
extern int check_repository_format(void);
@@ -691,7 +699,8 @@ extern void trace_argv_printf(const char **argv, const char *format, ...);
/* convert.c */
/* returns 1 if *dst was used */
-extern int convert_to_git(const char *path, const char *src, size_t len, struct strbuf *dst);
+extern int convert_to_git(const char *path, const char *src, size_t len,
+ struct strbuf *dst, enum safe_crlf checksafe);
extern int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst);
/* add */
diff --git a/config.c b/config.c
index 7881bbc778..8064cae182 100644
--- a/config.c
+++ b/config.c
@@ -415,6 +415,15 @@ int git_default_config(const char *var, const char *value)
return 0;
}
+ if (!strcmp(var, "core.safecrlf")) {
+ if (value && !strcasecmp(value, "warn")) {
+ safe_crlf = SAFE_CRLF_WARN;
+ return 0;
+ }
+ safe_crlf = git_config_bool(var, value);
+ return 0;
+ }
+
if (!strcmp(var, "user.name")) {
if (!value)
return config_error_nonbool(var);
diff --git a/convert.c b/convert.c
index 552707e8e6..d8c94cb3ed 100644
--- a/convert.c
+++ b/convert.c
@@ -85,8 +85,39 @@ static int is_binary(unsigned long size, struct text_stat *stats)
return 0;
}
+static void check_safe_crlf(const char *path, int action,
+ struct text_stat *stats, enum safe_crlf checksafe)
+{
+ if (!checksafe)
+ return;
+
+ if (action == CRLF_INPUT || auto_crlf <= 0) {
+ /*
+ * CRLFs would not be restored by checkout:
+ * check if we'd remove CRLFs
+ */
+ if (stats->crlf) {
+ if (checksafe == SAFE_CRLF_WARN)
+ warning("CRLF will be replaced by LF in %s.", path);
+ else /* i.e. SAFE_CRLF_FAIL */
+ die("CRLF would be replaced by LF in %s.", path);
+ }
+ } else if (auto_crlf > 0) {
+ /*
+ * CRLFs would be added by checkout:
+ * check if we have "naked" LFs
+ */
+ if (stats->lf != stats->crlf) {
+ if (checksafe == SAFE_CRLF_WARN)
+ warning("LF will be replaced by CRLF in %s", path);
+ else /* i.e. SAFE_CRLF_FAIL */
+ die("LF would be replaced by CRLF in %s", path);
+ }
+ }
+}
+
static int crlf_to_git(const char *path, const char *src, size_t len,
- struct strbuf *buf, int action)
+ struct strbuf *buf, int action, enum safe_crlf checksafe)
{
struct text_stat stats;
char *dst;
@@ -95,9 +126,6 @@ static int crlf_to_git(const char *path, const char *src, size_t len,
return 0;
gather_stats(src, len, &stats);
- /* No CR? Nothing to convert, regardless. */
- if (!stats.cr)
- return 0;
if (action == CRLF_GUESS) {
/*
@@ -115,6 +143,12 @@ static int crlf_to_git(const char *path, const char *src, size_t len,
return 0;
}
+ check_safe_crlf(path, action, &stats, checksafe);
+
+ /* Optimization: No CR? Nothing to convert, regardless. */
+ if (!stats.cr)
+ return 0;
+
/* only grow if not in place */
if (strbuf_avail(buf) + buf->len < len)
strbuf_grow(buf, len - buf->len);
@@ -536,7 +570,8 @@ static int git_path_check_ident(const char *path, struct git_attr_check *check)
return !!ATTR_TRUE(value);
}
-int convert_to_git(const char *path, const char *src, size_t len, struct strbuf *dst)
+int convert_to_git(const char *path, const char *src, size_t len,
+ struct strbuf *dst, enum safe_crlf checksafe)
{
struct git_attr_check check[3];
int crlf = CRLF_GUESS;
@@ -558,7 +593,7 @@ int convert_to_git(const char *path, const char *src, size_t len, struct strbuf
src = dst->buf;
len = dst->len;
}
- ret |= crlf_to_git(path, src, len, dst, crlf);
+ ret |= crlf_to_git(path, src, len, dst, crlf, checksafe);
if (ret) {
src = dst->buf;
len = dst->len;
diff --git a/diff.c b/diff.c
index 41ec2ced78..58fe7750f9 100644
--- a/diff.c
+++ b/diff.c
@@ -1631,7 +1631,7 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
* Convert from working tree format to canonical git format
*/
strbuf_init(&buf, 0);
- if (convert_to_git(s->path, s->data, s->size, &buf)) {
+ if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
size_t size = 0;
munmap(s->data, s->size);
s->should_munmap = 0;
diff --git a/environment.c b/environment.c
index fa3633372b..3527f1663f 100644
--- a/environment.c
+++ b/environment.c
@@ -35,6 +35,7 @@ int pager_use_color = 1;
const char *editor_program;
const char *excludes_file;
int auto_crlf = 0; /* 1: both ways, -1: only when adding git objects */
+enum safe_crlf safe_crlf = SAFE_CRLF_WARN;
unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
/* This is set by setup_git_dir_gently() and/or git_default_config() */
diff --git a/sha1_file.c b/sha1_file.c
index 66a4e00fa8..41799492f9 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2358,7 +2358,8 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
struct strbuf nbuf;
strbuf_init(&nbuf, 0);
- if (convert_to_git(path, buf, size, &nbuf)) {
+ if (convert_to_git(path, buf, size, &nbuf,
+ write_object ? safe_crlf : 0)) {
munmap(buf, size);
buf = strbuf_detach(&nbuf, &size);
re_allocated = 1;
diff --git a/t/t0020-crlf.sh b/t/t0020-crlf.sh
index 8b27aa892b..90ea081db6 100755
--- a/t/t0020-crlf.sh
+++ b/t/t0020-crlf.sh
@@ -8,6 +8,10 @@ q_to_nul () {
tr Q '\000'
}
+q_to_cr () {
+ tr Q '\015'
+}
+
append_cr () {
sed -e 's/$/Q/' | tr Q '\015'
}
@@ -42,6 +46,60 @@ test_expect_success setup '
echo happy.
'
+test_expect_success 'safecrlf: autocrlf=input, all CRLF' '
+
+ git config core.autocrlf input &&
+ git config core.safecrlf true &&
+
+ for w in I am all CRLF; do echo $w; done | append_cr >allcrlf &&
+ ! git add allcrlf
+'
+
+test_expect_success 'safecrlf: autocrlf=input, mixed LF/CRLF' '
+
+ git config core.autocrlf input &&
+ git config core.safecrlf true &&
+
+ for w in Oh here is CRLFQ in text; do echo $w; done | q_to_cr >mixed &&
+ ! git add mixed
+'
+
+test_expect_success 'safecrlf: autocrlf=true, all LF' '
+
+ git config core.autocrlf true &&
+ git config core.safecrlf true &&
+
+ for w in I am all LF; do echo $w; done >alllf &&
+ ! git add alllf
+'
+
+test_expect_success 'safecrlf: autocrlf=true mixed LF/CRLF' '
+
+ git config core.autocrlf true &&
+ git config core.safecrlf true &&
+
+ for w in Oh here is CRLFQ in text; do echo $w; done | q_to_cr >mixed &&
+ ! git add mixed
+'
+
+test_expect_success 'safecrlf: print warning only once' '
+
+ git config core.autocrlf input &&
+ git config core.safecrlf warn &&
+
+ for w in I am all LF; do echo $w; done >doublewarn &&
+ git add doublewarn &&
+ git commit -m "nowarn" &&
+ for w in Oh here is CRLFQ in text; do echo $w; done | q_to_cr >doublewarn &&
+ test $(git add doublewarn 2>&1 | grep "CRLF will be replaced by LF" | wc -l) = 1
+'
+
+test_expect_success 'switch off autocrlf, safecrlf, reset HEAD' '
+ git config core.autocrlf false &&
+ git config core.safecrlf false &&
+ git reset --hard HEAD^
+'
+
test_expect_success 'update with autocrlf=input' '
rm -f tmp one dir/two three &&