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-rw-r--r--convert.c276
1 files changed, 275 insertions, 1 deletions
diff --git a/convert.c b/convert.c
index c480097..64d0d30 100644
--- a/convert.c
+++ b/convert.c
@@ -7,6 +7,7 @@
#include "sigchain.h"
#include "pkt-line.h"
#include "sub-process.h"
+#include "utf8.h"
/*
* convert.c - convert a file when checking it out and checking it in.
@@ -265,6 +266,241 @@ static int will_convert_lf_to_crlf(size_t len, struct text_stat *stats,
}
+static int validate_encoding(const char *path, const char *enc,
+ const char *data, size_t len, int die_on_error)
+{
+ /* We only check for UTF here as UTF?? can be an alias for UTF-?? */
+ if (istarts_with(enc, "UTF")) {
+ /*
+ * Check for detectable errors in UTF encodings
+ */
+ if (has_prohibited_utf_bom(enc, data, len)) {
+ const char *error_msg = _(
+ "BOM is prohibited in '%s' if encoded as %s");
+ /*
+ * This advice is shown for UTF-??BE and UTF-??LE encodings.
+ * We cut off the last two characters of the encoding name
+ * to generate the encoding name suitable for BOMs.
+ */
+ const char *advise_msg = _(
+ "The file '%s' contains a byte order "
+ "mark (BOM). Please use UTF-%s as "
+ "working-tree-encoding.");
+ const char *stripped = NULL;
+ char *upper = xstrdup_toupper(enc);
+ upper[strlen(upper)-2] = '\0';
+ if (!skip_prefix(upper, "UTF-", &stripped))
+ skip_prefix(stripped, "UTF", &stripped);
+ advise(advise_msg, path, stripped);
+ free(upper);
+ if (die_on_error)
+ die(error_msg, path, enc);
+ else {
+ return error(error_msg, path, enc);
+ }
+
+ } else if (is_missing_required_utf_bom(enc, data, len)) {
+ const char *error_msg = _(
+ "BOM is required in '%s' if encoded as %s");
+ const char *advise_msg = _(
+ "The file '%s' is missing a byte order "
+ "mark (BOM). Please use UTF-%sBE or UTF-%sLE "
+ "(depending on the byte order) as "
+ "working-tree-encoding.");
+ const char *stripped = NULL;
+ char *upper = xstrdup_toupper(enc);
+ if (!skip_prefix(upper, "UTF-", &stripped))
+ skip_prefix(stripped, "UTF", &stripped);
+ advise(advise_msg, path, stripped, stripped);
+ free(upper);
+ if (die_on_error)
+ die(error_msg, path, enc);
+ else {
+ return error(error_msg, path, enc);
+ }
+ }
+
+ }
+ return 0;
+}
+
+static void trace_encoding(const char *context, const char *path,
+ const char *encoding, const char *buf, size_t len)
+{
+ static struct trace_key coe = TRACE_KEY_INIT(WORKING_TREE_ENCODING);
+ struct strbuf trace = STRBUF_INIT;
+ int i;
+
+ strbuf_addf(&trace, "%s (%s, considered %s):\n", context, path, encoding);
+ for (i = 0; i < len && buf; ++i) {
+ strbuf_addf(
+ &trace,"| \e[2m%2i:\e[0m %2x \e[2m%c\e[0m%c",
+ i,
+ (unsigned char) buf[i],
+ (buf[i] > 32 && buf[i] < 127 ? buf[i] : ' '),
+ ((i+1) % 8 && (i+1) < len ? ' ' : '\n')
+ );
+ }
+ strbuf_addchars(&trace, '\n', 1);
+
+ trace_strbuf(&coe, &trace);
+ strbuf_release(&trace);
+}
+
+static int check_roundtrip(const char *enc_name)
+{
+ /*
+ * check_roundtrip_encoding contains a string of comma and/or
+ * space separated encodings (eg. "UTF-16, ASCII, CP1125").
+ * Search for the given encoding in that string.
+ */
+ const char *found = strcasestr(check_roundtrip_encoding, enc_name);
+ const char *next;
+ int len;
+ if (!found)
+ return 0;
+ next = found + strlen(enc_name);
+ len = strlen(check_roundtrip_encoding);
+ return (found && (
+ /*
+ * check that the found encoding is at the
+ * beginning of check_roundtrip_encoding or
+ * that it is prefixed with a space or comma
+ */
+ found == check_roundtrip_encoding || (
+ (isspace(found[-1]) || found[-1] == ',')
+ )
+ ) && (
+ /*
+ * check that the found encoding is at the
+ * end of check_roundtrip_encoding or
+ * that it is suffixed with a space or comma
+ */
+ next == check_roundtrip_encoding + len || (
+ next < check_roundtrip_encoding + len &&
+ (isspace(next[0]) || next[0] == ',')
+ )
+ ));
+}
+
+static const char *default_encoding = "UTF-8";
+
+static int encode_to_git(const char *path, const char *src, size_t src_len,
+ struct strbuf *buf, const char *enc, int conv_flags)
+{
+ char *dst;
+ int dst_len;
+ int die_on_error = conv_flags & CONV_WRITE_OBJECT;
+
+ /*
+ * No encoding is specified or there is nothing to encode.
+ * Tell the caller that the content was not modified.
+ */
+ if (!enc || (src && !src_len))
+ return 0;
+
+ /*
+ * Looks like we got called from "would_convert_to_git()".
+ * This means Git wants to know if it would encode (= modify!)
+ * the content. Let's answer with "yes", since an encoding was
+ * specified.
+ */
+ if (!buf && !src)
+ return 1;
+
+ if (validate_encoding(path, enc, src, src_len, die_on_error))
+ return 0;
+
+ trace_encoding("source", path, enc, src, src_len);
+ dst = reencode_string_len(src, src_len, default_encoding, enc,
+ &dst_len);
+ if (!dst) {
+ /*
+ * We could add the blob "as-is" to Git. However, on checkout
+ * we would try to reencode to the original encoding. This
+ * would fail and we would leave the user with a messed-up
+ * working tree. Let's try to avoid this by screaming loud.
+ */
+ const char* msg = _("failed to encode '%s' from %s to %s");
+ if (die_on_error)
+ die(msg, path, enc, default_encoding);
+ else {
+ error(msg, path, enc, default_encoding);
+ return 0;
+ }
+ }
+ trace_encoding("destination", path, default_encoding, dst, dst_len);
+
+ /*
+ * UTF supports lossless conversion round tripping [1] and conversions
+ * between UTF and other encodings are mostly round trip safe as
+ * Unicode aims to be a superset of all other character encodings.
+ * However, certain encodings (e.g. SHIFT-JIS) are known to have round
+ * trip issues [2]. Check the round trip conversion for all encodings
+ * listed in core.checkRoundtripEncoding.
+ *
+ * The round trip check is only performed if content is written to Git.
+ * This ensures that no information is lost during conversion to/from
+ * the internal UTF-8 representation.
+ *
+ * Please note, the code below is not tested because I was not able to
+ * generate a faulty round trip without an iconv error. Iconv errors
+ * are already caught above.
+ *
+ * [1] http://unicode.org/faq/utf_bom.html#gen2
+ * [2] https://support.microsoft.com/en-us/help/170559/prb-conversion-problem-between-shift-jis-and-unicode
+ */
+ if (die_on_error && check_roundtrip(enc)) {
+ char *re_src;
+ int re_src_len;
+
+ re_src = reencode_string_len(dst, dst_len,
+ enc, default_encoding,
+ &re_src_len);
+
+ trace_printf("Checking roundtrip encoding for %s...\n", enc);
+ trace_encoding("reencoded source", path, enc,
+ re_src, re_src_len);
+
+ if (!re_src || src_len != re_src_len ||
+ memcmp(src, re_src, src_len)) {
+ const char* msg = _("encoding '%s' from %s to %s and "
+ "back is not the same");
+ die(msg, path, enc, default_encoding);
+ }
+
+ free(re_src);
+ }
+
+ strbuf_attach(buf, dst, dst_len, dst_len + 1);
+ return 1;
+}
+
+static int encode_to_worktree(const char *path, const char *src, size_t src_len,
+ struct strbuf *buf, const char *enc)
+{
+ char *dst;
+ int dst_len;
+
+ /*
+ * No encoding is specified or there is nothing to encode.
+ * Tell the caller that the content was not modified.
+ */
+ if (!enc || (src && !src_len))
+ return 0;
+
+ dst = reencode_string_len(src, src_len, enc, default_encoding,
+ &dst_len);
+ if (!dst) {
+ error("failed to encode '%s' from %s to %s",
+ path, default_encoding, enc);
+ return 0;
+ }
+
+ strbuf_attach(buf, dst, dst_len, dst_len + 1);
+ return 1;
+}
+
static int crlf_to_git(const struct index_state *istate,
const char *path, const char *src, size_t len,
struct strbuf *buf,
@@ -978,6 +1214,24 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
return 1;
}
+static const char *git_path_check_encoding(struct attr_check_item *check)
+{
+ const char *value = check->value;
+
+ if (ATTR_UNSET(value) || !strlen(value))
+ return NULL;
+
+ if (ATTR_TRUE(value) || ATTR_FALSE(value)) {
+ die(_("true/false are no valid working-tree-encodings"));
+ }
+
+ /* Don't encode to the default encoding */
+ if (same_encoding(value, default_encoding))
+ return NULL;
+
+ return value;
+}
+
static enum crlf_action git_path_check_crlf(struct attr_check_item *check)
{
const char *value = check->value;
@@ -1033,6 +1287,7 @@ struct conv_attrs {
enum crlf_action attr_action; /* What attr says */
enum crlf_action crlf_action; /* When no attr is set, use core.autocrlf */
int ident;
+ const char *working_tree_encoding; /* Supported encoding or default encoding if NULL */
};
static void convert_attrs(struct conv_attrs *ca, const char *path)
@@ -1041,7 +1296,8 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
if (!check) {
check = attr_check_initl("crlf", "ident", "filter",
- "eol", "text", NULL);
+ "eol", "text", "working-tree-encoding",
+ NULL);
user_convert_tail = &user_convert;
git_config(read_convert_config, NULL);
}
@@ -1064,6 +1320,7 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
else if (eol_attr == EOL_CRLF)
ca->crlf_action = CRLF_TEXT_CRLF;
}
+ ca->working_tree_encoding = git_path_check_encoding(ccheck + 5);
} else {
ca->drv = NULL;
ca->crlf_action = CRLF_UNDEFINED;
@@ -1144,6 +1401,13 @@ int convert_to_git(const struct index_state *istate,
src = dst->buf;
len = dst->len;
}
+
+ ret |= encode_to_git(path, src, len, dst, ca.working_tree_encoding, conv_flags);
+ if (ret && dst) {
+ src = dst->buf;
+ len = dst->len;
+ }
+
if (!(conv_flags & CONV_EOL_KEEP_CRLF)) {
ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, conv_flags);
if (ret && dst) {
@@ -1167,6 +1431,7 @@ void convert_to_git_filter_fd(const struct index_state *istate,
if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL))
die("%s: clean filter '%s' failed", path, ca.drv->name);
+ encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags);
crlf_to_git(istate, path, dst->buf, dst->len, dst, ca.crlf_action, conv_flags);
ident_to_git(path, dst->buf, dst->len, dst, ca.ident);
}
@@ -1198,6 +1463,12 @@ static int convert_to_working_tree_internal(const char *path, const char *src,
}
}
+ ret |= encode_to_worktree(path, src, len, dst, ca.working_tree_encoding);
+ if (ret) {
+ src = dst->buf;
+ len = dst->len;
+ }
+
ret_filter = apply_filter(
path, src, len, -1, dst, ca.drv, CAP_SMUDGE, dco);
if (!ret_filter && ca.drv && ca.drv->required)
@@ -1664,6 +1935,9 @@ struct stream_filter *get_stream_filter(const char *path, const struct object_id
if (ca.drv && (ca.drv->process || ca.drv->smudge || ca.drv->clean))
return NULL;
+ if (ca.working_tree_encoding)
+ return NULL;
+
if (ca.crlf_action == CRLF_AUTO || ca.crlf_action == CRLF_AUTO_CRLF)
return NULL;