From c29807b27dc60e17eb1cd8bc50900af2a09ce66f Mon Sep 17 00:00:00 2001 From: Paul Tan Date: Tue, 4 Aug 2015 21:51:27 +0800 Subject: [PATCH] builtin-am: auto-detect mbox patches Since 15ced75 (git-am foreign patch support: autodetect some patch formats, 2009-05-27), git-am.sh is able to autodetect mbox, stgit and mercurial patches through heuristics. Re-implement support for autodetecting mbox/maildir files in builtin/am.c. RFC 2822 requires that lines are terminated by "\r\n". To support this, implement strbuf_getline_crlf(), which will remove both '\n' and "\r\n" from the end of the line. Helped-by: Junio C Hamano Helped-by: Eric Sunshine Helped-by: Johannes Schindelin Signed-off-by: Paul Tan Signed-off-by: Junio C Hamano --- builtin/am.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) diff --git a/builtin/am.c b/builtin/am.c index 5f3c131357..c12566ab4a 100644 --- a/builtin/am.c +++ b/builtin/am.c @@ -10,6 +10,21 @@ #include "dir.h" #include "run-command.h" +/** + * Like strbuf_getline(), but treats both '\n' and "\r\n" as line terminators. + */ +static int strbuf_getline_crlf(struct strbuf *sb, FILE *fp) +{ + if (strbuf_getwholeline(sb, fp, '\n')) + return EOF; + if (sb->buf[sb->len - 1] == '\n') { + strbuf_setlen(sb, sb->len - 1); + if (sb->len > 0 && sb->buf[sb->len - 1] == '\r') + strbuf_setlen(sb, sb->len - 1); + } + return 0; +} + enum patch_format { PATCH_FORMAT_UNKNOWN = 0, PATCH_FORMAT_MBOX @@ -128,6 +143,92 @@ static void am_destroy(const struct am_state *state) } /** + * Determines if the file looks like a piece of RFC2822 mail by grabbing all + * non-indented lines and checking if they look like they begin with valid + * header field names. + * + * Returns 1 if the file looks like a piece of mail, 0 otherwise. + */ +static int is_mail(FILE *fp) +{ + const char *header_regex = "^[!-9;-~]+:"; + struct strbuf sb = STRBUF_INIT; + regex_t regex; + int ret = 1; + + if (fseek(fp, 0L, SEEK_SET)) + die_errno(_("fseek failed")); + + if (regcomp(®ex, header_regex, REG_NOSUB | REG_EXTENDED)) + die("invalid pattern: %s", header_regex); + + while (!strbuf_getline_crlf(&sb, fp)) { + if (!sb.len) + break; /* End of header */ + + /* Ignore indented folded lines */ + if (*sb.buf == '\t' || *sb.buf == ' ') + continue; + + /* It's a header if it matches header_regex */ + if (regexec(®ex, sb.buf, 0, NULL, 0)) { + ret = 0; + goto done; + } + } + +done: + regfree(®ex); + strbuf_release(&sb); + return ret; +} + +/** + * Attempts to detect the patch_format of the patches contained in `paths`, + * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if + * detection fails. + */ +static int detect_patch_format(const char **paths) +{ + enum patch_format ret = PATCH_FORMAT_UNKNOWN; + struct strbuf l1 = STRBUF_INIT; + FILE *fp; + + /* + * We default to mbox format if input is from stdin and for directories + */ + if (!*paths || !strcmp(*paths, "-") || is_directory(*paths)) + return PATCH_FORMAT_MBOX; + + /* + * Otherwise, check the first few lines of the first patch, starting + * from the first non-blank line, to try to detect its format. + */ + + fp = xfopen(*paths, "r"); + + while (!strbuf_getline_crlf(&l1, fp)) { + if (l1.len) + break; + } + + if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) { + ret = PATCH_FORMAT_MBOX; + goto done; + } + + if (l1.len && is_mail(fp)) { + ret = PATCH_FORMAT_MBOX; + goto done; + } + +done: + fclose(fp); + strbuf_release(&l1); + return ret; +} + +/** * Splits out individual email patches from `paths`, where each path is either * a mbox file or a Maildir. Returns 0 on success, -1 on failure. */ @@ -185,6 +286,14 @@ static int split_mail(struct am_state *state, enum patch_format patch_format, static void am_setup(struct am_state *state, enum patch_format patch_format, const char **paths) { + if (!patch_format) + patch_format = detect_patch_format(paths); + + if (!patch_format) { + fprintf_ln(stderr, _("Patch format detection failed.")); + exit(128); + } + if (mkdir(state->dir, 0777) < 0 && errno != EEXIST) die_errno(_("failed to create directory '%s'"), state->dir); -- 2.11.4.GIT