builtin-am: apply patch with git-apply
[gitweb.git] / builtin / am.c
index ac172c484101c7834bcf6ec75ef26aad60bf6310..1f198e4f31a972b19e61c3352b4332483be31d2f 100644 (file)
@@ -8,6 +8,53 @@
 #include "exec_cmd.h"
 #include "parse-options.h"
 #include "dir.h"
+#include "run-command.h"
+#include "quote.h"
+#include "lockfile.h"
+
+/**
+ * Returns 1 if the file is empty or does not exist, 0 otherwise.
+ */
+static int is_empty_file(const char *filename)
+{
+       struct stat st;
+
+       if (stat(filename, &st) < 0) {
+               if (errno == ENOENT)
+                       return 1;
+               die_errno(_("could not stat %s"), filename);
+       }
+
+       return !st.st_size;
+}
+
+/**
+ * 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;
+}
+
+/**
+ * Returns the length of the first line of msg.
+ */
+static int linelen(const char *msg)
+{
+       return strchrnul(msg, '\n') - msg;
+}
+
+enum patch_format {
+       PATCH_FORMAT_UNKNOWN = 0,
+       PATCH_FORMAT_MBOX
+};
 
 struct am_state {
        /* state directory path */
@@ -16,6 +63,16 @@ struct am_state {
        /* current and last patch numbers, 1-indexed */
        int cur;
        int last;
+
+       /* commit metadata and message */
+       char *author_name;
+       char *author_email;
+       char *author_date;
+       char *msg;
+       size_t msg_len;
+
+       /* number of digits in patch filename */
+       int prec;
 };
 
 /**
@@ -28,6 +85,8 @@ static void am_state_init(struct am_state *state, const char *dir)
 
        assert(dir);
        state->dir = xstrdup(dir);
+
+       state->prec = 4;
 }
 
 /**
@@ -36,6 +95,10 @@ static void am_state_init(struct am_state *state, const char *dir)
 static void am_state_release(struct am_state *state)
 {
        free(state->dir);
+       free(state->author_name);
+       free(state->author_email);
+       free(state->author_date);
+       free(state->msg);
 }
 
 /**
@@ -85,6 +148,161 @@ static int read_state_file(struct strbuf *sb, const struct am_state *state,
        die_errno(_("could not read '%s'"), am_path(state, file));
 }
 
+/**
+ * Reads a KEY=VALUE shell variable assignment from `fp`, returning the VALUE
+ * as a newly-allocated string. VALUE must be a quoted string, and the KEY must
+ * match `key`. Returns NULL on failure.
+ *
+ * This is used by read_author_script() to read the GIT_AUTHOR_* variables from
+ * the author-script.
+ */
+static char *read_shell_var(FILE *fp, const char *key)
+{
+       struct strbuf sb = STRBUF_INIT;
+       const char *str;
+
+       if (strbuf_getline(&sb, fp, '\n'))
+               goto fail;
+
+       if (!skip_prefix(sb.buf, key, &str))
+               goto fail;
+
+       if (!skip_prefix(str, "=", &str))
+               goto fail;
+
+       strbuf_remove(&sb, 0, str - sb.buf);
+
+       str = sq_dequote(sb.buf);
+       if (!str)
+               goto fail;
+
+       return strbuf_detach(&sb, NULL);
+
+fail:
+       strbuf_release(&sb);
+       return NULL;
+}
+
+/**
+ * Reads and parses the state directory's "author-script" file, and sets
+ * state->author_name, state->author_email and state->author_date accordingly.
+ * Returns 0 on success, -1 if the file could not be parsed.
+ *
+ * The author script is of the format:
+ *
+ *     GIT_AUTHOR_NAME='$author_name'
+ *     GIT_AUTHOR_EMAIL='$author_email'
+ *     GIT_AUTHOR_DATE='$author_date'
+ *
+ * where $author_name, $author_email and $author_date are quoted. We are strict
+ * with our parsing, as the file was meant to be eval'd in the old git-am.sh
+ * script, and thus if the file differs from what this function expects, it is
+ * better to bail out than to do something that the user does not expect.
+ */
+static int read_author_script(struct am_state *state)
+{
+       const char *filename = am_path(state, "author-script");
+       FILE *fp;
+
+       assert(!state->author_name);
+       assert(!state->author_email);
+       assert(!state->author_date);
+
+       fp = fopen(filename, "r");
+       if (!fp) {
+               if (errno == ENOENT)
+                       return 0;
+               die_errno(_("could not open '%s' for reading"), filename);
+       }
+
+       state->author_name = read_shell_var(fp, "GIT_AUTHOR_NAME");
+       if (!state->author_name) {
+               fclose(fp);
+               return -1;
+       }
+
+       state->author_email = read_shell_var(fp, "GIT_AUTHOR_EMAIL");
+       if (!state->author_email) {
+               fclose(fp);
+               return -1;
+       }
+
+       state->author_date = read_shell_var(fp, "GIT_AUTHOR_DATE");
+       if (!state->author_date) {
+               fclose(fp);
+               return -1;
+       }
+
+       if (fgetc(fp) != EOF) {
+               fclose(fp);
+               return -1;
+       }
+
+       fclose(fp);
+       return 0;
+}
+
+/**
+ * Saves state->author_name, state->author_email and state->author_date in the
+ * state directory's "author-script" file.
+ */
+static void write_author_script(const struct am_state *state)
+{
+       struct strbuf sb = STRBUF_INIT;
+
+       strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
+       sq_quote_buf(&sb, state->author_name);
+       strbuf_addch(&sb, '\n');
+
+       strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
+       sq_quote_buf(&sb, state->author_email);
+       strbuf_addch(&sb, '\n');
+
+       strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
+       sq_quote_buf(&sb, state->author_date);
+       strbuf_addch(&sb, '\n');
+
+       write_file(am_path(state, "author-script"), 1, "%s", sb.buf);
+
+       strbuf_release(&sb);
+}
+
+/**
+ * Reads the commit message from the state directory's "final-commit" file,
+ * setting state->msg to its contents and state->msg_len to the length of its
+ * contents in bytes.
+ *
+ * Returns 0 on success, -1 if the file does not exist.
+ */
+static int read_commit_msg(struct am_state *state)
+{
+       struct strbuf sb = STRBUF_INIT;
+
+       assert(!state->msg);
+
+       if (read_state_file(&sb, state, "final-commit", 0) < 0) {
+               strbuf_release(&sb);
+               return -1;
+       }
+
+       state->msg = strbuf_detach(&sb, &state->msg_len);
+       return 0;
+}
+
+/**
+ * Saves state->msg in the state directory's "final-commit" file.
+ */
+static void write_commit_msg(const struct am_state *state)
+{
+       int fd;
+       const char *filename = am_path(state, "final-commit");
+
+       fd = xopen(filename, O_WRONLY | O_CREAT, 0666);
+       if (write_in_full(fd, state->msg, state->msg_len) < 0)
+               die_errno(_("could not write to %s"), filename);
+       close(fd);
+}
+
 /**
  * Loads state from disk.
  */
@@ -100,6 +318,11 @@ static void am_load(struct am_state *state)
                die("BUG: state file 'last' does not exist");
        state->last = strtol(sb.buf, NULL, 10);
 
+       if (read_author_script(state) < 0)
+               die(_("could not parse author script"));
+
+       read_commit_msg(state);
+
        strbuf_release(&sb);
 }
 
@@ -116,14 +339,166 @@ static void am_destroy(const struct am_state *state)
        strbuf_release(&sb);
 }
 
+/**
+ * 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(&regex, 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(&regex, sb.buf, 0, NULL, 0)) {
+                       ret = 0;
+                       goto done;
+               }
+       }
+
+done:
+       regfree(&regex);
+       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.
+ */
+static int split_mail_mbox(struct am_state *state, const char **paths)
+{
+       struct child_process cp = CHILD_PROCESS_INIT;
+       struct strbuf last = STRBUF_INIT;
+
+       cp.git_cmd = 1;
+       argv_array_push(&cp.args, "mailsplit");
+       argv_array_pushf(&cp.args, "-d%d", state->prec);
+       argv_array_pushf(&cp.args, "-o%s", state->dir);
+       argv_array_push(&cp.args, "-b");
+       argv_array_push(&cp.args, "--");
+       argv_array_pushv(&cp.args, paths);
+
+       if (capture_command(&cp, &last, 8))
+               return -1;
+
+       state->cur = 1;
+       state->last = strtol(last.buf, NULL, 10);
+
+       return 0;
+}
+
+/**
+ * Splits a list of files/directories into individual email patches. Each path
+ * in `paths` must be a file/directory that is formatted according to
+ * `patch_format`.
+ *
+ * Once split out, the individual email patches will be stored in the state
+ * directory, with each patch's filename being its index, padded to state->prec
+ * digits.
+ *
+ * state->cur will be set to the index of the first mail, and state->last will
+ * be set to the index of the last mail.
+ *
+ * Returns 0 on success, -1 on failure.
+ */
+static int split_mail(struct am_state *state, enum patch_format patch_format,
+                       const char **paths)
+{
+       switch (patch_format) {
+       case PATCH_FORMAT_MBOX:
+               return split_mail_mbox(state, paths);
+       default:
+               die("BUG: invalid patch_format");
+       }
+       return -1;
+}
+
 /**
  * Setup a new am session for applying patches
  */
-static void am_setup(struct am_state *state)
+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);
 
+       if (split_mail(state, patch_format, paths) < 0) {
+               am_destroy(state);
+               die(_("Failed to split patches."));
+       }
+
        /*
         * NOTE: Since the "next" and "last" files determine if an am_state
         * session is in progress, they should be written last.
@@ -140,28 +515,231 @@ static void am_setup(struct am_state *state)
  */
 static void am_next(struct am_state *state)
 {
+       free(state->author_name);
+       state->author_name = NULL;
+
+       free(state->author_email);
+       state->author_email = NULL;
+
+       free(state->author_date);
+       state->author_date = NULL;
+
+       free(state->msg);
+       state->msg = NULL;
+       state->msg_len = 0;
+
+       unlink(am_path(state, "author-script"));
+       unlink(am_path(state, "final-commit"));
+
        state->cur++;
        write_file(am_path(state, "next"), 1, "%d", state->cur);
 }
 
+/**
+ * Returns the filename of the current patch email.
+ */
+static const char *msgnum(const struct am_state *state)
+{
+       static struct strbuf sb = STRBUF_INIT;
+
+       strbuf_reset(&sb);
+       strbuf_addf(&sb, "%0*d", state->prec, state->cur);
+
+       return sb.buf;
+}
+
+/**
+ * Refresh and write index.
+ */
+static void refresh_and_write_cache(void)
+{
+       struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
+
+       hold_locked_index(lock_file, 1);
+       refresh_cache(REFRESH_QUIET);
+       if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
+               die(_("unable to write index file"));
+}
+
+/**
+ * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
+ * state->msg will be set to the patch message. state->author_name,
+ * state->author_email and state->author_date will be set to the patch author's
+ * name, email and date respectively. The patch body will be written to the
+ * state directory's "patch" file.
+ *
+ * Returns 1 if the patch should be skipped, 0 otherwise.
+ */
+static int parse_mail(struct am_state *state, const char *mail)
+{
+       FILE *fp;
+       struct child_process cp = CHILD_PROCESS_INIT;
+       struct strbuf sb = STRBUF_INIT;
+       struct strbuf msg = STRBUF_INIT;
+       struct strbuf author_name = STRBUF_INIT;
+       struct strbuf author_date = STRBUF_INIT;
+       struct strbuf author_email = STRBUF_INIT;
+       int ret = 0;
+
+       cp.git_cmd = 1;
+       cp.in = xopen(mail, O_RDONLY, 0);
+       cp.out = xopen(am_path(state, "info"), O_WRONLY | O_CREAT, 0777);
+
+       argv_array_push(&cp.args, "mailinfo");
+       argv_array_push(&cp.args, am_path(state, "msg"));
+       argv_array_push(&cp.args, am_path(state, "patch"));
+
+       if (run_command(&cp) < 0)
+               die("could not parse patch");
+
+       close(cp.in);
+       close(cp.out);
+
+       /* Extract message and author information */
+       fp = xfopen(am_path(state, "info"), "r");
+       while (!strbuf_getline(&sb, fp, '\n')) {
+               const char *x;
+
+               if (skip_prefix(sb.buf, "Subject: ", &x)) {
+                       if (msg.len)
+                               strbuf_addch(&msg, '\n');
+                       strbuf_addstr(&msg, x);
+               } else if (skip_prefix(sb.buf, "Author: ", &x))
+                       strbuf_addstr(&author_name, x);
+               else if (skip_prefix(sb.buf, "Email: ", &x))
+                       strbuf_addstr(&author_email, x);
+               else if (skip_prefix(sb.buf, "Date: ", &x))
+                       strbuf_addstr(&author_date, x);
+       }
+       fclose(fp);
+
+       /* Skip pine's internal folder data */
+       if (!strcmp(author_name.buf, "Mail System Internal Data")) {
+               ret = 1;
+               goto finish;
+       }
+
+       if (is_empty_file(am_path(state, "patch"))) {
+               printf_ln(_("Patch is empty. Was it split wrong?"));
+               exit(128);
+       }
+
+       strbuf_addstr(&msg, "\n\n");
+       if (strbuf_read_file(&msg, am_path(state, "msg"), 0) < 0)
+               die_errno(_("could not read '%s'"), am_path(state, "msg"));
+       stripspace(&msg, 0);
+
+       assert(!state->author_name);
+       state->author_name = strbuf_detach(&author_name, NULL);
+
+       assert(!state->author_email);
+       state->author_email = strbuf_detach(&author_email, NULL);
+
+       assert(!state->author_date);
+       state->author_date = strbuf_detach(&author_date, NULL);
+
+       assert(!state->msg);
+       state->msg = strbuf_detach(&msg, &state->msg_len);
+
+finish:
+       strbuf_release(&msg);
+       strbuf_release(&author_date);
+       strbuf_release(&author_email);
+       strbuf_release(&author_name);
+       strbuf_release(&sb);
+       return ret;
+}
+
+/**
+ * Applies current patch with git-apply. Returns 0 on success, -1 otherwise.
+ */
+static int run_apply(const struct am_state *state)
+{
+       struct child_process cp = CHILD_PROCESS_INIT;
+
+       cp.git_cmd = 1;
+
+       argv_array_push(&cp.args, "apply");
+       argv_array_push(&cp.args, "--index");
+       argv_array_push(&cp.args, am_path(state, "patch"));
+
+       if (run_command(&cp))
+               return -1;
+
+       /* Reload index as git-apply will have modified it. */
+       discard_cache();
+       read_cache();
+
+       return 0;
+}
+
 /**
  * Applies all queued mail.
  */
 static void am_run(struct am_state *state)
 {
+       refresh_and_write_cache();
+
        while (state->cur <= state->last) {
+               const char *mail = am_path(state, msgnum(state));
+
+               if (!file_exists(mail))
+                       goto next;
+
+               if (parse_mail(state, mail))
+                       goto next; /* mail should be skipped */
+
+               write_author_script(state);
+               write_commit_msg(state);
+
+               printf_ln(_("Applying: %.*s"), linelen(state->msg), state->msg);
+
+               if (run_apply(state) < 0) {
+                       int advice_amworkdir = 1;
+
+                       printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
+                               linelen(state->msg), state->msg);
+
+                       git_config_get_bool("advice.amworkdir", &advice_amworkdir);
+
+                       if (advice_amworkdir)
+                               printf_ln(_("The copy of the patch that failed is found in: %s"),
+                                               am_path(state, "patch"));
+
+                       exit(128);
+               }
 
-               /* NEEDSWORK: Patch application not implemented yet */
+               /*
+                * NEEDSWORK: After the patch has been applied to the index
+                * with git-apply, we need to make commit as well.
+                */
 
+next:
                am_next(state);
        }
 
        am_destroy(state);
 }
 
+/**
+ * parse_options() callback that validates and sets opt->value to the
+ * PATCH_FORMAT_* enum value corresponding to `arg`.
+ */
+static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
+{
+       int *opt_value = opt->value;
+
+       if (!strcmp(arg, "mbox"))
+               *opt_value = PATCH_FORMAT_MBOX;
+       else
+               return error(_("Invalid value for --patch-format: %s"), arg);
+       return 0;
+}
+
 int cmd_am(int argc, const char **argv, const char *prefix)
 {
        struct am_state state;
+       int patch_format = PATCH_FORMAT_UNKNOWN;
 
        const char * const usage[] = {
                N_("git am [options] [(<mbox>|<Maildir>)...]"),
@@ -169,6 +747,9 @@ int cmd_am(int argc, const char **argv, const char *prefix)
        };
 
        struct option options[] = {
+               OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
+                       N_("format the patch(es) are in"),
+                       parse_opt_patchformat),
                OPT_END()
        };
 
@@ -193,10 +774,26 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 
        argc = parse_options(argc, argv, prefix, options, usage, 0);
 
+       if (read_index_preload(&the_index, NULL) < 0)
+               die(_("failed to read the index"));
+
        if (am_in_progress(&state))
                am_load(&state);
-       else
-               am_setup(&state);
+       else {
+               struct argv_array paths = ARGV_ARRAY_INIT;
+               int i;
+
+               for (i = 0; i < argc; i++) {
+                       if (is_absolute_path(argv[i]) || !prefix)
+                               argv_array_push(&paths, argv[i]);
+                       else
+                               argv_array_push(&paths, mkpath("%s/%s", prefix, argv[i]));
+               }
+
+               am_setup(&state, patch_format, paths.argv);
+
+               argv_array_clear(&paths);
+       }
 
        am_run(&state);