{"thread":{"id":"20332","subject":"[PATCH v2 1/5] revert: libify pick","startedAt":"2009-08-01T15:46:02Z","lastAt":"2009-08-01T15:46:02Z","messageCount":1,"participants":["Christian Couder"],"isPatch":true,"patchVersion":2,"patchTotal":5},"messages":[{"id":"119341","messageId":"20090801154607.20922.87382.chriscool@tuxfamily.org","threadId":"20332","inReplyTo":null,"subject":"[PATCH v2 1/5] revert: libify pick","fromName":"Christian Couder","fromEmail":"chriscool@tuxfamily.org","sentAt":"2009-08-01T15:46:02Z","receivedAt":"2009-08-01T15:46:02Z","isPatch":true,"sender":{"key":"christian.couder@gmail.com","avatar":"https://avatars.githubusercontent.com/u/208954?v=4"},"body":"From: Stephan Beyer <s-beyer@gmx.net>\n\nThis commit is made of code from the sequencer GSoC project:\n\ngit://repo.or.cz/git/sbeyer.git\n\n(commit e7b8dab0c2a73ade92017a52bb1405ea1534ef20)\n\nThe goal of this commit is to abstract out pick functionnality\ninto a new pick() function made of code from \"builtin-revert.c\".\n\nThe new pick() function is in a new \"pick.c\" file with an\nassociated \"pick.h\".\n\n\"pick.h\" and \"pick.c\" are strictly the same as on the sequencer repo,\nbut a few changes were needed on \"builtin-revert.c\" to keep it up to\ndate with changes on git.git.\n\nMentored-by: Daniel Barkalow <barkalow@iabervon.org>\nMentored-by: Christian Couder <chriscool@tuxfamily.org>\nSigned-off-by: Stephan Beyer <s-beyer@gmx.net>\nSigned-off-by: Christian Couder <chriscool@tuxfamily.org>\n---\n Makefile         |    2 +\n builtin-revert.c |  272 +++++++++---------------------------------------------\n pick.c           |  229 +++++++++++++++++++++++++++++++++++++++++++++\n pick.h           |   13 +++\n 4 files changed, 288 insertions(+), 228 deletions(-)\n create mode 100644 pick.c\n create mode 100644 pick.h\n\ndiff --git a/Makefile b/Makefile\nindex 6b39d56..139a7b7 100644\n--- a/Makefile\n+++ b/Makefile\n@@ -438,6 +438,7 @@ LIB_H += pack-refs.h\n LIB_H += pack-revindex.h\n LIB_H += parse-options.h\n LIB_H += patch-ids.h\n+LIB_H += pick.h\n LIB_H += pkt-line.h\n LIB_H += progress.h\n LIB_H += quote.h\n@@ -526,6 +527,7 @@ LIB_OBJS += parse-options.o\n LIB_OBJS += patch-delta.o\n LIB_OBJS += patch-ids.o\n LIB_OBJS += path.o\n+LIB_OBJS += pick.o\n LIB_OBJS += pkt-line.o\n LIB_OBJS += preload-index.o\n LIB_OBJS += pretty.o\ndiff --git a/builtin-revert.c b/builtin-revert.c\nindex 151aa6a..6dd29a3 100644\n--- a/builtin-revert.c\n+++ b/builtin-revert.c\n@@ -1,18 +1,14 @@\n #include \"cache.h\"\n #include \"builtin.h\"\n-#include \"object.h\"\n #include \"commit.h\"\n #include \"tag.h\"\n-#include \"wt-status.h\"\n-#include \"run-command.h\"\n #include \"exec_cmd.h\"\n #include \"utf8.h\"\n #include \"parse-options.h\"\n-#include \"cache-tree.h\"\n #include \"diff.h\"\n #include \"revision.h\"\n #include \"rerere.h\"\n-#include \"merge-recursive.h\"\n+#include \"pick.h\"\n \n /*\n  * This implements the builtins revert and cherry-pick.\n@@ -35,25 +31,23 @@ static const char * const cherry_pick_usage[] = {\n \tNULL\n };\n \n-static int edit, no_replay, no_commit, mainline, signoff;\n-static enum { REVERT, CHERRY_PICK } action;\n+static int edit, no_commit, mainline, signoff;\n+static int flags;\n static struct commit *commit;\n \n-static const char *me;\n-\n #define GIT_REFLOG_ACTION \"GIT_REFLOG_ACTION\"\n \n static void parse_args(int argc, const char **argv)\n {\n \tconst char * const * usage_str =\n-\t\taction == REVERT ?  revert_usage : cherry_pick_usage;\n+\t\tflags & PICK_REVERSE ? revert_usage : cherry_pick_usage;\n \tunsigned char sha1[20];\n \tconst char *arg;\n \tint noop;\n \tstruct option options[] = {\n \t\tOPT_BOOLEAN('n', \"no-commit\", &no_commit, \"don't automatically commit\"),\n \t\tOPT_BOOLEAN('e', \"edit\", &edit, \"edit the commit message\"),\n-\t\tOPT_BOOLEAN('x', NULL, &no_replay, \"append commit name when cherry-picking\"),\n+\t\tOPT_BIT('x', NULL, &flags, \"append commit name when cherry-picking\", PICK_ADD_NOTE),\n \t\tOPT_BOOLEAN('r', NULL, &noop, \"no-op (backward compatibility)\"),\n \t\tOPT_BOOLEAN('s', \"signoff\", &signoff, \"add Signed-off-by:\"),\n \t\tOPT_INTEGER('m', \"mainline\", &mainline, \"parent number\"),\n@@ -77,42 +71,12 @@ static void parse_args(int argc, const char **argv)\n \t\tdie (\"'%s' does not point to a commit\", arg);\n }\n \n-static char *get_oneline(const char *message)\n-{\n-\tchar *result;\n-\tconst char *p = message, *abbrev, *eol;\n-\tint abbrev_len, oneline_len;\n-\n-\tif (!p)\n-\t\tdie (\"Could not read commit message of %s\",\n-\t\t\t\tsha1_to_hex(commit->object.sha1));\n-\twhile (*p && (*p != '\\n' || p[1] != '\\n'))\n-\t\tp++;\n-\n-\tif (*p) {\n-\t\tp += 2;\n-\t\tfor (eol = p + 1; *eol && *eol != '\\n'; eol++)\n-\t\t\t; /* do nothing */\n-\t} else\n-\t\teol = p;\n-\tabbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);\n-\tabbrev_len = strlen(abbrev);\n-\toneline_len = eol - p;\n-\tresult = xmalloc(abbrev_len + 5 + oneline_len);\n-\tmemcpy(result, abbrev, abbrev_len);\n-\tmemcpy(result + abbrev_len, \"... \", 4);\n-\tmemcpy(result + abbrev_len + 4, p, oneline_len);\n-\tresult[abbrev_len + 4 + oneline_len] = '\\0';\n-\treturn result;\n-}\n-\n static char *get_encoding(const char *message)\n {\n \tconst char *p = message, *eol;\n \n \tif (!p)\n-\t\tdie (\"Could not read commit message of %s\",\n-\t\t\t\tsha1_to_hex(commit->object.sha1));\n+\t\treturn NULL;\n \twhile (*p && *p != '\\n') {\n \t\tfor (eol = p + 1; *eol && *eol != '\\n'; eol++)\n \t\t\t; /* do nothing */\n@@ -128,30 +92,6 @@ static char *get_encoding(const char *message)\n \treturn NULL;\n }\n \n-static struct lock_file msg_file;\n-static int msg_fd;\n-\n-static void add_to_msg(const char *string)\n-{\n-\tint len = strlen(string);\n-\tif (write_in_full(msg_fd, string, len) < 0)\n-\t\tdie_errno (\"Could not write to MERGE_MSG\");\n-}\n-\n-static void add_message_to_msg(const char *message)\n-{\n-\tconst char *p = message;\n-\twhile (*p && (*p != '\\n' || p[1] != '\\n'))\n-\t\tp++;\n-\n-\tif (!*p)\n-\t\tadd_to_msg(sha1_to_hex(commit->object.sha1));\n-\n-\tp += 2;\n-\tadd_to_msg(p);\n-\treturn;\n-}\n-\n static void set_author_ident_env(const char *message)\n {\n \tconst char *p = message;\n@@ -214,7 +154,7 @@ static char *help_msg(const unsigned char *sha1)\n \t       \"mark the corrected paths with 'git add <paths>' \"\n \t       \"or 'git rm <paths>' and commit the result.\");\n \n-\tif (action == CHERRY_PICK) {\n+\tif (!(flags & PICK_REVERSE)) {\n \t\tsprintf(helpbuf + strlen(helpbuf),\n \t\t\t\"\\nWhen commiting, use the option \"\n \t\t\t\"'-c %s' to retain authorship and message.\",\n@@ -223,187 +163,68 @@ static char *help_msg(const unsigned char *sha1)\n \treturn helpbuf;\n }\n \n-static struct tree *empty_tree(void)\n+static void write_message(struct strbuf *msgbuf, const char *filename)\n {\n-\tstruct tree *tree = xcalloc(1, sizeof(struct tree));\n-\n-\ttree->object.parsed = 1;\n-\ttree->object.type = OBJ_TREE;\n-\tpretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);\n-\treturn tree;\n+\tstruct lock_file msg_file;\n+\tint msg_fd;\n+\tmsg_fd = hold_lock_file_for_update(&msg_file, filename,\n+\t\t\t\t\t   LOCK_DIE_ON_ERROR);\n+\tif (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)\n+\t\tdie_errno(\"Could not write to %s.\", filename);\n+\tstrbuf_release(msgbuf);\n+\tif (commit_lock_file(&msg_file) < 0)\n+\t\tdie(\"Error wrapping up %s\", filename);\n }\n \n static int revert_or_cherry_pick(int argc, const char **argv)\n {\n-\tunsigned char head[20];\n-\tstruct commit *base, *next, *parent;\n-\tint i, index_fd, clean;\n-\tchar *oneline, *reencoded_message = NULL;\n-\tconst char *message, *encoding;\n-\tchar *defmsg = git_pathdup(\"MERGE_MSG\");\n-\tstruct merge_options o;\n-\tstruct tree *result, *next_tree, *base_tree, *head_tree;\n-\tstatic struct lock_file index_lock;\n+\tconst char *me;\n+\tstruct strbuf msgbuf;\n+\tchar *reencoded_message = NULL;\n+\tconst char *encoding;\n+\tint failed;\n \n \tgit_config(git_default_config, NULL);\n-\tme = action == REVERT ? \"revert\" : \"cherry-pick\";\n+\tme = flags & PICK_REVERSE ? \"revert\" : \"cherry-pick\";\n \tsetenv(GIT_REFLOG_ACTION, me, 0);\n \tparse_args(argc, argv);\n \n-\t/* this is copied from the shell script, but it's never triggered... */\n-\tif (action == REVERT && !no_replay)\n-\t\tdie(\"revert is incompatible with replay\");\n-\n \tif (read_cache() < 0)\n \t\tdie(\"git %s: failed to read the index\", me);\n-\tif (no_commit) {\n-\t\t/*\n-\t\t * We do not intend to commit immediately.  We just want to\n-\t\t * merge the differences in, so let's compute the tree\n-\t\t * that represents the \"current\" state for merge-recursive\n-\t\t * to work on.\n-\t\t */\n-\t\tif (write_cache_as_tree(head, 0, NULL))\n-\t\t\tdie (\"Your index file is unmerged.\");\n-\t} else {\n-\t\tif (get_sha1(\"HEAD\", head))\n-\t\t\tdie (\"You do not have a valid HEAD\");\n-\t\tif (index_differs_from(\"HEAD\", 0))\n-\t\t\tdie (\"Dirty index: cannot %s\", me);\n-\t}\n-\tdiscard_cache();\n-\n-\tindex_fd = hold_locked_index(&index_lock, 1);\n+\tif (!no_commit && index_differs_from(\"HEAD\", 0))\n+\t\tdie (\"Dirty index: cannot %s\", me);\n \n-\tif (!commit->parents) {\n-\t\tif (action == REVERT)\n-\t\t\tdie (\"Cannot revert a root commit\");\n-\t\tparent = NULL;\n-\t}\n-\telse if (commit->parents->next) {\n-\t\t/* Reverting or cherry-picking a merge commit */\n-\t\tint cnt;\n-\t\tstruct commit_list *p;\n-\n-\t\tif (!mainline)\n-\t\t\tdie(\"Commit %s is a merge but no -m option was given.\",\n-\t\t\t    sha1_to_hex(commit->object.sha1));\n-\n-\t\tfor (cnt = 1, p = commit->parents;\n-\t\t     cnt != mainline && p;\n-\t\t     cnt++)\n-\t\t\tp = p->next;\n-\t\tif (cnt != mainline || !p)\n-\t\t\tdie(\"Commit %s does not have parent %d\",\n-\t\t\t    sha1_to_hex(commit->object.sha1), mainline);\n-\t\tparent = p->item;\n-\t} else if (0 < mainline)\n-\t\tdie(\"Mainline was specified but commit %s is not a merge.\",\n-\t\t    sha1_to_hex(commit->object.sha1));\n-\telse\n-\t\tparent = commit->parents->item;\n-\n-\tif (!(message = commit->buffer))\n-\t\tdie (\"Cannot get commit message for %s\",\n+\tif (!commit->buffer)\n+\t\treturn error(\"Cannot get commit message for %s\",\n \t\t\t\tsha1_to_hex(commit->object.sha1));\n-\n-\tif (parent && parse_commit(parent) < 0)\n-\t\tdie(\"%s: cannot parse parent commit %s\",\n-\t\t    me, sha1_to_hex(parent->object.sha1));\n-\n-\t/*\n-\t * \"commit\" is an existing commit.  We would want to apply\n-\t * the difference it introduces since its first parent \"prev\"\n-\t * on top of the current HEAD if we are cherry-pick.  Or the\n-\t * reverse of it if we are revert.\n-\t */\n-\n-\tmsg_fd = hold_lock_file_for_update(&msg_file, defmsg,\n-\t\t\t\t\t   LOCK_DIE_ON_ERROR);\n-\n-\tencoding = get_encoding(message);\n+\tencoding = get_encoding(commit->buffer);\n \tif (!encoding)\n \t\tencoding = \"UTF-8\";\n \tif (!git_commit_encoding)\n \t\tgit_commit_encoding = \"UTF-8\";\n-\tif ((reencoded_message = reencode_string(message,\n+\tif ((reencoded_message = reencode_string(commit->buffer,\n \t\t\t\t\tgit_commit_encoding, encoding)))\n-\t\tmessage = reencoded_message;\n-\n-\toneline = get_oneline(message);\n-\n-\tif (action == REVERT) {\n-\t\tchar *oneline_body = strchr(oneline, ' ');\n+\t\tcommit->buffer = reencoded_message;\n \n-\t\tbase = commit;\n-\t\tnext = parent;\n-\t\tadd_to_msg(\"Revert \\\"\");\n-\t\tadd_to_msg(oneline_body + 1);\n-\t\tadd_to_msg(\"\\\"\\n\\nThis reverts commit \");\n-\t\tadd_to_msg(sha1_to_hex(commit->object.sha1));\n-\n-\t\tif (commit->parents->next) {\n-\t\t\tadd_to_msg(\", reversing\\nchanges made to \");\n-\t\t\tadd_to_msg(sha1_to_hex(parent->object.sha1));\n-\t\t}\n-\t\tadd_to_msg(\".\\n\");\n-\t} else {\n-\t\tbase = parent;\n-\t\tnext = commit;\n-\t\tset_author_ident_env(message);\n-\t\tadd_message_to_msg(message);\n-\t\tif (no_replay) {\n-\t\t\tadd_to_msg(\"(cherry picked from commit \");\n-\t\t\tadd_to_msg(sha1_to_hex(commit->object.sha1));\n-\t\t\tadd_to_msg(\")\\n\");\n-\t\t}\n-\t}\n-\n-\tread_cache();\n-\tinit_merge_options(&o);\n-\to.branch1 = \"HEAD\";\n-\to.branch2 = oneline;\n-\n-\thead_tree = parse_tree_indirect(head);\n-\tnext_tree = next ? next->tree : empty_tree();\n-\tbase_tree = base ? base->tree : empty_tree();\n-\n-\tclean = merge_trees(&o,\n-\t\t\t    head_tree,\n-\t\t\t    next_tree, base_tree, &result);\n-\n-\tif (active_cache_changed &&\n-\t    (write_cache(index_fd, active_cache, active_nr) ||\n-\t     commit_locked_index(&index_lock)))\n-\t\tdie(\"%s: Unable to write new index file\", me);\n-\trollback_lock_file(&index_lock);\n-\n-\tif (!clean) {\n-\t\tadd_to_msg(\"\\nConflicts:\\n\\n\");\n-\t\tfor (i = 0; i < active_nr;) {\n-\t\t\tstruct cache_entry *ce = active_cache[i++];\n-\t\t\tif (ce_stage(ce)) {\n-\t\t\t\tadd_to_msg(\"\\t\");\n-\t\t\t\tadd_to_msg(ce->name);\n-\t\t\t\tadd_to_msg(\"\\n\");\n-\t\t\t\twhile (i < active_nr && !strcmp(ce->name,\n-\t\t\t\t\t\tactive_cache[i]->name))\n-\t\t\t\t\ti++;\n-\t\t\t}\n-\t\t}\n-\t\tif (commit_lock_file(&msg_file) < 0)\n-\t\t\tdie (\"Error wrapping up %s\", defmsg);\n+\tfailed = pick(commit, mainline, flags, &msgbuf);\n+\tif (failed < 0) {\n+\t\texit(1);\n+\t} else if (failed > 0) {\n \t\tfprintf(stderr, \"Automatic %s failed.%s\\n\",\n \t\t\tme, help_msg(commit->object.sha1));\n+\t\twrite_message(&msgbuf, git_path(\"MERGE_MSG\"));\n \t\trerere();\n \t\texit(1);\n \t}\n-\tif (commit_lock_file(&msg_file) < 0)\n-\t\tdie (\"Error wrapping up %s\", defmsg);\n+\tif (!(flags & PICK_REVERSE))\n+\t\tset_author_ident_env(commit->buffer);\n+\tfree(reencoded_message);\n+\n \tfprintf(stderr, \"Finished one %s.\\n\", me);\n \n+\twrite_message(&msgbuf, git_path(\"MERGE_MSG\"));\n+\n \t/*\n-\t *\n \t * If we are cherry-pick, and if the merge did not result in\n \t * hand-editing, we will hit this commit and inherit the original\n \t * author date and name.\n@@ -421,14 +242,11 @@ static int revert_or_cherry_pick(int argc, const char **argv)\n \t\t\targs[i++] = \"-s\";\n \t\tif (!edit) {\n \t\t\targs[i++] = \"-F\";\n-\t\t\targs[i++] = defmsg;\n+\t\t\targs[i++] = git_path(\"MERGE_MSG\");\n \t\t}\n \t\targs[i] = NULL;\n \t\treturn execv_git_cmd(args);\n \t}\n-\tfree(reencoded_message);\n-\tfree(defmsg);\n-\n \treturn 0;\n }\n \n@@ -436,14 +254,12 @@ int cmd_revert(int argc, const char **argv, const char *prefix)\n {\n \tif (isatty(0))\n \t\tedit = 1;\n-\tno_replay = 1;\n-\taction = REVERT;\n+\tflags = PICK_REVERSE | PICK_ADD_NOTE;\n \treturn revert_or_cherry_pick(argc, argv);\n }\n \n int cmd_cherry_pick(int argc, const char **argv, const char *prefix)\n {\n-\tno_replay = 0;\n-\taction = CHERRY_PICK;\n+\tflags = 0;\n \treturn revert_or_cherry_pick(argc, argv);\n }\ndiff --git a/pick.c b/pick.c\nnew file mode 100644\nindex 0000000..77c7169\n--- /dev/null\n+++ b/pick.c\n@@ -0,0 +1,229 @@\n+#include \"cache.h\"\n+#include \"commit.h\"\n+#include \"run-command.h\"\n+#include \"cache-tree.h\"\n+#include \"pick.h\"\n+#include \"merge-recursive.h\"\n+\n+static struct commit *commit;\n+\n+static char *get_oneline(const char *message)\n+{\n+\tchar *result;\n+\tconst char *p = message, *abbrev, *eol;\n+\tint abbrev_len, oneline_len;\n+\n+\tif (!p)\n+\t\treturn NULL;\n+\twhile (*p && (*p != '\\n' || p[1] != '\\n'))\n+\t\tp++;\n+\n+\tif (*p) {\n+\t\tp += 2;\n+\t\tfor (eol = p + 1; *eol && *eol != '\\n'; eol++)\n+\t\t\t; /* do nothing */\n+\t} else\n+\t\teol = p;\n+\tabbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);\n+\tabbrev_len = strlen(abbrev);\n+\toneline_len = eol - p;\n+\tresult = xmalloc(abbrev_len + 5 + oneline_len);\n+\tmemcpy(result, abbrev, abbrev_len);\n+\tmemcpy(result + abbrev_len, \"... \", 4);\n+\tmemcpy(result + abbrev_len + 4, p, oneline_len);\n+\tresult[abbrev_len + 4 + oneline_len] = '\\0';\n+\treturn result;\n+}\n+\n+static void add_message_to_msg(struct strbuf *msg, const char *message)\n+{\n+\tconst char *p = message;\n+\twhile (*p && (*p != '\\n' || p[1] != '\\n'))\n+\t\tp++;\n+\n+\tif (!*p)\n+\t\tstrbuf_addstr(msg, sha1_to_hex(commit->object.sha1));\n+\n+\tp += 2;\n+\tstrbuf_addstr(msg, p);\n+\treturn;\n+}\n+\n+static struct tree *empty_tree(void)\n+{\n+\tstruct tree *tree = xcalloc(1, sizeof(struct tree));\n+\n+\ttree->object.parsed = 1;\n+\ttree->object.type = OBJ_TREE;\n+\tpretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);\n+\treturn tree;\n+}\n+\n+/*\n+ * Pick changes introduced by pick_commit into current working tree\n+ * and index.\n+ *\n+ * Return 0 on success.\n+ * Return negative value on error before picking,\n+ * and a positive value after picking,\n+ * and return 1 if and only if a conflict occurs but no other error.\n+ */\n+int pick(struct commit *pick_commit, int mainline, int flags,\n+\t\t\t\t\t\tstruct strbuf *msg)\n+{\n+\tunsigned char head[20];\n+\tstruct commit *base, *next, *parent;\n+\tint i, index_fd, clean;\n+\tint ret = 0;\n+\tchar *oneline;\n+\tconst char *message;\n+\tstruct merge_options o;\n+\tstruct tree *result, *next_tree, *base_tree, *head_tree;\n+\tstatic struct lock_file index_lock;\n+\n+\tstrbuf_init(msg, 0);\n+\tcommit = pick_commit;\n+\n+\tif (flags & PICK_REVERSE) /* REVERSE implies ADD_NOTE */\n+\t\tflags |= PICK_ADD_NOTE;\n+\n+\t/*\n+\t * We do not intend to commit immediately.  We just want to\n+\t * merge the differences in, so let's compute the tree\n+\t * that represents the \"current\" state for merge-recursive\n+\t * to work on.\n+\t */\n+\tif (write_cache_as_tree(head, 0, NULL)) {\n+\t\terror(\"Your index file is unmerged.\");\n+\t\treturn -1;\n+\t}\n+\tdiscard_cache();\n+\n+\tindex_fd = hold_locked_index(&index_lock, 0);\n+\tif (index_fd < 0) {\n+\t\terror(\"Unable to create locked index: %s\",\n+\t\t\t\t\t\tstrerror(errno));\n+\t\treturn -1;\n+\t}\n+\n+\tif (!commit->parents) {\n+\t\tif (flags & PICK_REVERSE) {\n+\t\t\terror(\"Cannot revert a root commit\");\n+\t\t\treturn -1;\n+\t\t}\n+\t\tparent = NULL;\n+\t}\n+\telse if (commit->parents->next) {\n+\t\t/* Reverting or cherry-picking a merge commit */\n+\t\tint cnt;\n+\t\tstruct commit_list *p;\n+\n+\t\tif (!mainline) {\n+\t\t\terror(\"Commit %s is a merge but no mainline was given.\",\n+\t\t\t    sha1_to_hex(commit->object.sha1));\n+\t\t\treturn -1;\n+\t\t}\n+\n+\t\tfor (cnt = 1, p = commit->parents;\n+\t\t     cnt != mainline && p;\n+\t\t     cnt++)\n+\t\t\tp = p->next;\n+\t\tif (cnt != mainline || !p) {\n+\t\t\terror(\"Commit %s does not have parent %d\",\n+\t\t\t    sha1_to_hex(commit->object.sha1), mainline);\n+\t\t\treturn -1;\n+\t\t}\n+\t\tparent = p->item;\n+\t} else if (0 < mainline) {\n+\t\terror(\"Mainline was specified but commit %s is not a merge.\",\n+\t\t    sha1_to_hex(commit->object.sha1));\n+\t\treturn -1;\n+\t} else\n+\t\tparent = commit->parents->item;\n+\n+\tif (!(message = commit->buffer)) {\n+\t\terror(\"Cannot get commit message for %s\",\n+\t\t\t\tsha1_to_hex(commit->object.sha1));\n+\t\treturn -1;\n+\t}\n+\n+\tif (parent && parse_commit(parent) < 0) {\n+\t\terror(\"Cannot parse parent commit %s\",\n+\t\t      sha1_to_hex(parent->object.sha1));\n+\t\treturn -1;\n+\t}\n+\n+\toneline = get_oneline(message);\n+\n+\tif (flags & PICK_REVERSE) {\n+\t\tchar *oneline_body = strchr(oneline, ' ');\n+\n+\t\tbase = commit;\n+\t\tnext = parent;\n+\t\tstrbuf_addstr(msg, \"Revert \\\"\");\n+\t\tstrbuf_addstr(msg, oneline_body + 1);\n+\t\tstrbuf_addstr(msg, \"\\\"\\n\\nThis reverts commit \");\n+\t\tstrbuf_addstr(msg, sha1_to_hex(commit->object.sha1));\n+\n+\t\tif (commit->parents->next) {\n+\t\t\tstrbuf_addstr(msg, \", reversing\\nchanges made to \");\n+\t\t\tstrbuf_addstr(msg, sha1_to_hex(parent->object.sha1));\n+\t\t}\n+\t\tstrbuf_addstr(msg, \".\\n\");\n+\t} else {\n+\t\tbase = parent;\n+\t\tnext = commit;\n+\t\tadd_message_to_msg(msg, message);\n+\t\tif (flags & PICK_ADD_NOTE) {\n+\t\t\tstrbuf_addstr(msg, \"(cherry picked from commit \");\n+\t\t\tstrbuf_addstr(msg, sha1_to_hex(commit->object.sha1));\n+\t\t\tstrbuf_addstr(msg, \")\\n\");\n+\t\t}\n+\t}\n+\n+\tread_cache();\n+\tinit_merge_options(&o);\n+\to.branch1 = \"HEAD\";\n+\to.branch2 = oneline;\n+\n+\thead_tree = parse_tree_indirect(head);\n+\tnext_tree = next ? next->tree : empty_tree();\n+\tbase_tree = base ? base->tree : empty_tree();\n+\n+\tclean = merge_trees(&o,\n+\t\t\t    head_tree,\n+\t\t\t    next_tree, base_tree, &result);\n+\n+\tif (active_cache_changed &&\n+\t    (write_cache(index_fd, active_cache, active_nr) ||\n+\t     commit_locked_index(&index_lock))) {\n+\t\terror(\"Unable to write new index file\");\n+\t\treturn 2;\n+\t}\n+\trollback_lock_file(&index_lock);\n+\n+\tif (!clean) {\n+\t\tstrbuf_addstr(msg, \"\\nConflicts:\\n\\n\");\n+\t\tfor (i = 0; i < active_nr;) {\n+\t\t\tstruct cache_entry *ce = active_cache[i++];\n+\t\t\tif (ce_stage(ce)) {\n+\t\t\t\tstrbuf_addstr(msg, \"\\t\");\n+\t\t\t\tstrbuf_addstr(msg, ce->name);\n+\t\t\t\tstrbuf_addstr(msg, \"\\n\");\n+\t\t\t\twhile (i < active_nr && !strcmp(ce->name,\n+\t\t\t\t\t\tactive_cache[i]->name))\n+\t\t\t\t\ti++;\n+\t\t\t}\n+\t\t}\n+\t\tret = 1;\n+\t}\n+\tfree(oneline);\n+\n+\tdiscard_cache();\n+\tif (read_cache() < 0) {\n+\t\terror(\"Cannot read the index\");\n+\t\treturn 2;\n+\t}\n+\n+\treturn ret;\n+}\ndiff --git a/pick.h b/pick.h\nnew file mode 100644\nindex 0000000..7eb0d3a\n--- /dev/null\n+++ b/pick.h\n@@ -0,0 +1,13 @@\n+#ifndef PICK_H\n+#define PICK_H\n+\n+#include \"commit.h\"\n+\n+/* Pick flags: */\n+#define PICK_REVERSE   1 /* pick the reverse changes (\"revert\") */\n+#define PICK_ADD_NOTE  2 /* add note about original commit (unless conflict) */\n+/* We don't need a PICK_QUIET. This is done by\n+ *\tsetenv(\"GIT_MERGE_VERBOSITY\", \"0\", 1); */\n+extern int pick(struct commit *pick_commit, int mainline, int flags, struct strbuf *msg);\n+\n+#endif\n-- \n1.6.4.133.g8a5c8\n"}]}