Merge branch 'mp/rebase-label-length-limit' into maint-2.42

[thirdparty/git.git] / sequencer.c

diff --git a/sequencer.c b/sequencer.c
index 7e6c556e0a684d6e9724f90a1be6e34f4ffe2c5f..828efd589deff91a67804951176b689d63a4cf18 100644 (file)
--- a/sequencer.c
+++ b/sequencer.c
@@ -1,7 +1,6 @@
 #include "git-compat-util.h"
 #include "abspath.h"
 #include "advice.h"
-#include "alloc.h"
 #include "config.h"
 #include "copy.h"
 #include "environment.h"
@@ -49,10 +48,18 @@
 #include "rebase-interactive.h"
 #include "reset.h"
 #include "branch.h"
-#include "wrapper.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
+/*
+ * To accommodate common filesystem limitations, where the loose refs' file
+ * names must not exceed `NAME_MAX`, the labels generated by `git rebase
+ * --rebase-merges` need to be truncated if the corresponding commit subjects
+ * are too long.
+ * Add some margin to stay clear from reaching `NAME_MAX`.
+ */
+#define GIT_MAX_LABEL_LENGTH ((NAME_MAX) - (LOCK_SUFFIX_LEN) - 16)
+
 static const char sign_off_header[] = "Signed-off-by: ";
 static const char cherry_picked_prefix[] = "(cherry picked from commit ";
 
@@ -2704,7 +2711,7 @@ int todo_list_parse_insn_buffer(struct repository *r, char *buf,
                if (fixup_okay)
                        ; /* do nothing */
                else if (is_fixup(item->command))
-                       return error(_("cannot '%s' without a previous commit"),
+                       res = error(_("cannot '%s' without a previous commit"),
                                command_to_string(item->command));
                else if (!is_noop(item->command))
                        fixup_okay = 1;
@@ -5050,19 +5057,31 @@ static int commit_staged_changes(struct repository *r,
                                 * We need to update the squash message to skip
                                 * the latest commit message.
                                 */
+                               int res = 0;
                                struct commit *commit;
+                               const char *msg;
                                const char *path = rebase_path_squash_msg();
                                const char *encoding = get_commit_output_encoding();
 
-                               if (parse_head(r, &commit) ||
-                                   !(p = repo_logmsg_reencode(r, commit, NULL, encoding)) ||
-                                   write_message(p, strlen(p), path, 0)) {
-                                       repo_unuse_commit_buffer(r, commit, p);
-                                       return error(_("could not write file: "
+                               if (parse_head(r, &commit))
+                                       return error(_("could not parse HEAD"));
+
+                               p = repo_logmsg_reencode(r, commit, NULL, encoding);
+                               if (!p)  {
+                                       res = error(_("could not parse commit %s"),
+                                                   oid_to_hex(&commit->object.oid));
+                                       goto unuse_commit_buffer;
+                               }
+                               find_commit_subject(p, &msg);
+                               if (write_message(msg, strlen(msg), path, 0)) {
+                                       res = error(_("could not write file: "
                                                       "'%s'"), path);
+                                       goto unuse_commit_buffer;
                                }
-                               repo_unuse_commit_buffer(r,
-                                                        commit, p);
+                       unuse_commit_buffer:
+                               repo_unuse_commit_buffer(r, commit, p);
+                               if (res)
+                                       return res;
                        }
                }
 
@@ -5342,6 +5361,7 @@ struct label_state {
        struct oidmap commit2label;
        struct hashmap labels;
        struct strbuf buf;
+       int max_label_length;
 };
 
 static const char *label_oid(struct object_id *oid, const char *label,
@@ -5398,6 +5418,8 @@ static const char *label_oid(struct object_id *oid, const char *label,
                }
        } else {
                struct strbuf *buf = &state->buf;
+               int label_is_utf8 = 1; /* start with this assumption */
+               size_t max_len = buf->len + state->max_label_length;
 
                /*
                 * Sanitize labels by replacing non-alpha-numeric characters
@@ -5406,14 +5428,34 @@ static const char *label_oid(struct object_id *oid, const char *label,
                 *
                 * Note that we retain non-ASCII UTF-8 characters (identified
                 * via the most significant bit). They should be all acceptable
-                * in file names. We do not validate the UTF-8 here, that's not
-                * the job of this function.
+                * in file names.
+                *
+                * As we will use the labels as names of (loose) refs, it is
+                * vital that the name not be longer than the maximum component
+                * size of the file system (`NAME_MAX`). We are careful to
+                * truncate the label accordingly, allowing for the `.lock`
+                * suffix and for the label to be UTF-8 encoded (i.e. we avoid
+                * truncating in the middle of a character).
                 */
-               for (; *label; label++)
-                       if ((*label & 0x80) || isalnum(*label))
+               for (; *label && buf->len + 1 < max_len; label++)
+                       if (isalnum(*label) ||
+                           (!label_is_utf8 && (*label & 0x80)))
                                strbuf_addch(buf, *label);
+                       else if (*label & 0x80) {
+                               const char *p = label;
+
+                               utf8_width(&p, NULL);
+                               if (p) {
+                                       if (buf->len + (p - label) > max_len)
+                                               break;
+                                       strbuf_add(buf, label, p - label);
+                                       label = p - 1;
+                               } else {
+                                       label_is_utf8 = 0;
+                                       strbuf_addch(buf, *label);
+                               }
                        /* avoid leading dash and double-dashes */
-                       else if (buf->len && buf->buf[buf->len - 1] != '-')
+                       } else if (buf->len && buf->buf[buf->len - 1] != '-')
                                strbuf_addch(buf, '-');
                if (!buf->len) {
                        strbuf_addstr(buf, "rev-");
@@ -5475,7 +5517,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
        struct string_entry *entry;
        struct oidset interesting = OIDSET_INIT, child_seen = OIDSET_INIT,
                shown = OIDSET_INIT;
-       struct label_state state = { OIDMAP_INIT, { NULL }, STRBUF_INIT };
+       struct label_state state =
+               { OIDMAP_INIT, { NULL }, STRBUF_INIT, GIT_MAX_LABEL_LENGTH };
 
        int abbr = flags & TODO_LIST_ABBREVIATE_CMDS;
        const char *cmd_pick = abbr ? "p" : "pick",
@@ -5483,6 +5526,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
                *cmd_reset = abbr ? "t" : "reset",
                *cmd_merge = abbr ? "m" : "merge";
 
+       git_config_get_int("rebase.maxlabellength", &state.max_label_length);
+
        oidmap_init(&commit2todo, 0);
        oidmap_init(&state.commit2label, 0);
        hashmap_init(&state.labels, labels_cmp, NULL, 0);