Revision b018ff60857ee7d79e3c4a8772bac08656a2a3c6 authored by Jeff King on 29 December 2012, 20:51:54 UTC, committed by Junio C Hamano on 04 November 2013, 18:13:27 UTC
When we call "read-tree --reset -u HEAD ORIG_HEAD", the first thing we
do with the index is to call read_cache_unmerged.  Originally that
would read the index, leaving aside any unmerged entries.  However, as
of d1a43f2 (reset --hard/read-tree --reset -u: remove unmerged new
paths, 2008-10-15), it actually creates a new cache entry to serve as
a placeholder, so that we later know to update the working tree.

However, we later noticed that the sha1 of that unmerged entry was
just copied from some higher stage, leaving you with random content in
the index.  That was fixed by e11d7b5 ("reset --merge": fix unmerged
case, 2009-12-31), which instead puts the null sha1 into the newly
created entry, and sets a CE_CONFLICTED flag. At the same time, it
teaches the unpack-trees machinery to pay attention to this flag, so
that oneway_merge throws away the current value.

However, it did not update the code paths for twoway_merge, which is
where we end up in the two-way read-tree with --reset. We notice that
the HEAD and ORIG_HEAD versions are the same, and say "oh, we can just
reuse the current version". But that's not true. The current version
is bogus.

Notice this case and make sure we do not keep the bogus entry; either
we do not have that path in the tree we are moving to (i.e. remove
it), or we want to have the cache entry we created for the tree we are
moving to (i.e. resolve by explicitly saying the "newtree" version is
what we want).

[jc: this is from the almost year-old $gmane/212316]

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent c479d14
Raw File
help.c
#include "cache.h"
#include "builtin.h"
#include "exec_cmd.h"
#include "levenshtein.h"
#include "help.h"
#include "common-cmds.h"

void add_cmdname(struct cmdnames *cmds, const char *name, int len)
{
	struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);

	ent->len = len;
	memcpy(ent->name, name, len);
	ent->name[len] = 0;

	ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
	cmds->names[cmds->cnt++] = ent;
}

static void clean_cmdnames(struct cmdnames *cmds)
{
	int i;
	for (i = 0; i < cmds->cnt; ++i)
		free(cmds->names[i]);
	free(cmds->names);
	cmds->cnt = 0;
	cmds->alloc = 0;
}

static int cmdname_compare(const void *a_, const void *b_)
{
	struct cmdname *a = *(struct cmdname **)a_;
	struct cmdname *b = *(struct cmdname **)b_;
	return strcmp(a->name, b->name);
}

static void uniq(struct cmdnames *cmds)
{
	int i, j;

	if (!cmds->cnt)
		return;

	for (i = j = 1; i < cmds->cnt; i++)
		if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
			cmds->names[j++] = cmds->names[i];

	cmds->cnt = j;
}

void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
{
	int ci, cj, ei;
	int cmp;

	ci = cj = ei = 0;
	while (ci < cmds->cnt && ei < excludes->cnt) {
		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
		if (cmp < 0)
			cmds->names[cj++] = cmds->names[ci++];
		else if (cmp == 0)
			ci++, ei++;
		else if (cmp > 0)
			ei++;
	}

	while (ci < cmds->cnt)
		cmds->names[cj++] = cmds->names[ci++];

	cmds->cnt = cj;
}

static void pretty_print_string_list(struct cmdnames *cmds, int longest)
{
	int cols = 1, rows;
	int space = longest + 1; /* min 1 SP between words */
	int max_cols = term_columns() - 1; /* don't print *on* the edge */
	int i, j;

	if (space < max_cols)
		cols = max_cols / space;
	rows = DIV_ROUND_UP(cmds->cnt, cols);

	for (i = 0; i < rows; i++) {
		printf("  ");

		for (j = 0; j < cols; j++) {
			int n = j * rows + i;
			int size = space;
			if (n >= cmds->cnt)
				break;
			if (j == cols-1 || n + rows >= cmds->cnt)
				size = 1;
			printf("%-*s", size, cmds->names[n]->name);
		}
		putchar('\n');
	}
}

static int is_executable(const char *name)
{
	struct stat st;

	if (stat(name, &st) || /* stat, not lstat */
	    !S_ISREG(st.st_mode))
		return 0;

#if defined(WIN32) || defined(__CYGWIN__)
#if defined(__CYGWIN__)
if ((st.st_mode & S_IXUSR) == 0)
#endif
{	/* cannot trust the executable bit, peek into the file instead */
	char buf[3] = { 0 };
	int n;
	int fd = open(name, O_RDONLY);
	st.st_mode &= ~S_IXUSR;
	if (fd >= 0) {
		n = read(fd, buf, 2);
		if (n == 2)
			/* DOS executables start with "MZ" */
			if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
				st.st_mode |= S_IXUSR;
		close(fd);
	}
}
#endif
	return st.st_mode & S_IXUSR;
}

static void list_commands_in_dir(struct cmdnames *cmds,
					 const char *path,
					 const char *prefix)
{
	int prefix_len;
	DIR *dir = opendir(path);
	struct dirent *de;
	struct strbuf buf = STRBUF_INIT;
	int len;

	if (!dir)
		return;
	if (!prefix)
		prefix = "git-";
	prefix_len = strlen(prefix);

	strbuf_addf(&buf, "%s/", path);
	len = buf.len;

	while ((de = readdir(dir)) != NULL) {
		int entlen;

		if (prefixcmp(de->d_name, prefix))
			continue;

		strbuf_setlen(&buf, len);
		strbuf_addstr(&buf, de->d_name);
		if (!is_executable(buf.buf))
			continue;

		entlen = strlen(de->d_name) - prefix_len;
		if (has_extension(de->d_name, ".exe"))
			entlen -= 4;

		add_cmdname(cmds, de->d_name + prefix_len, entlen);
	}
	closedir(dir);
	strbuf_release(&buf);
}

void load_command_list(const char *prefix,
		struct cmdnames *main_cmds,
		struct cmdnames *other_cmds)
{
	const char *env_path = getenv("PATH");
	const char *exec_path = git_exec_path();

	if (exec_path) {
		list_commands_in_dir(main_cmds, exec_path, prefix);
		qsort(main_cmds->names, main_cmds->cnt,
		      sizeof(*main_cmds->names), cmdname_compare);
		uniq(main_cmds);
	}

	if (env_path) {
		char *paths, *path, *colon;
		path = paths = xstrdup(env_path);
		while (1) {
			if ((colon = strchr(path, PATH_SEP)))
				*colon = 0;
			if (!exec_path || strcmp(path, exec_path))
				list_commands_in_dir(other_cmds, path, prefix);

			if (!colon)
				break;
			path = colon + 1;
		}
		free(paths);

		qsort(other_cmds->names, other_cmds->cnt,
		      sizeof(*other_cmds->names), cmdname_compare);
		uniq(other_cmds);
	}
	exclude_cmds(other_cmds, main_cmds);
}

void list_commands(const char *title, struct cmdnames *main_cmds,
		   struct cmdnames *other_cmds)
{
	int i, longest = 0;

	for (i = 0; i < main_cmds->cnt; i++)
		if (longest < main_cmds->names[i]->len)
			longest = main_cmds->names[i]->len;
	for (i = 0; i < other_cmds->cnt; i++)
		if (longest < other_cmds->names[i]->len)
			longest = other_cmds->names[i]->len;

	if (main_cmds->cnt) {
		const char *exec_path = git_exec_path();
		printf("available %s in '%s'\n", title, exec_path);
		printf("----------------");
		mput_char('-', strlen(title) + strlen(exec_path));
		putchar('\n');
		pretty_print_string_list(main_cmds, longest);
		putchar('\n');
	}

	if (other_cmds->cnt) {
		printf("%s available from elsewhere on your $PATH\n", title);
		printf("---------------------------------------");
		mput_char('-', strlen(title));
		putchar('\n');
		pretty_print_string_list(other_cmds, longest);
		putchar('\n');
	}
}

int is_in_cmdlist(struct cmdnames *c, const char *s)
{
	int i;
	for (i = 0; i < c->cnt; i++)
		if (!strcmp(s, c->names[i]->name))
			return 1;
	return 0;
}

static int autocorrect;
static struct cmdnames aliases;

static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
{
	if (!strcmp(var, "help.autocorrect"))
		autocorrect = git_config_int(var,value);
	/* Also use aliases for command lookup */
	if (!prefixcmp(var, "alias."))
		add_cmdname(&aliases, var + 6, strlen(var + 6));

	return git_default_config(var, value, cb);
}

static int levenshtein_compare(const void *p1, const void *p2)
{
	const struct cmdname *const *c1 = p1, *const *c2 = p2;
	const char *s1 = (*c1)->name, *s2 = (*c2)->name;
	int l1 = (*c1)->len;
	int l2 = (*c2)->len;
	return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
}

static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
{
	int i;
	ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);

	for (i = 0; i < old->cnt; i++)
		cmds->names[cmds->cnt++] = old->names[i];
	free(old->names);
	old->cnt = 0;
	old->names = NULL;
}

/* An empirically derived magic number */
#define SIMILARITY_FLOOR 7
#define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)

static const char bad_interpreter_advice[] =
	N_("'%s' appears to be a git command, but we were not\n"
	"able to execute it. Maybe git-%s is broken?");

const char *help_unknown_cmd(const char *cmd)
{
	int i, n, best_similarity = 0;
	struct cmdnames main_cmds, other_cmds;

	memset(&main_cmds, 0, sizeof(main_cmds));
	memset(&other_cmds, 0, sizeof(other_cmds));
	memset(&aliases, 0, sizeof(aliases));

	git_config(git_unknown_cmd_config, NULL);

	load_command_list("git-", &main_cmds, &other_cmds);

	add_cmd_list(&main_cmds, &aliases);
	add_cmd_list(&main_cmds, &other_cmds);
	qsort(main_cmds.names, main_cmds.cnt,
	      sizeof(main_cmds.names), cmdname_compare);
	uniq(&main_cmds);

	/* This abuses cmdname->len for levenshtein distance */
	for (i = 0, n = 0; i < main_cmds.cnt; i++) {
		int cmp = 0; /* avoid compiler stupidity */
		const char *candidate = main_cmds.names[i]->name;

		/*
		 * An exact match means we have the command, but
		 * for some reason exec'ing it gave us ENOENT; probably
		 * it's a bad interpreter in the #! line.
		 */
		if (!strcmp(candidate, cmd))
			die(_(bad_interpreter_advice), cmd, cmd);

		/* Does the candidate appear in common_cmds list? */
		while (n < ARRAY_SIZE(common_cmds) &&
		       (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
			n++;
		if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
			/* Yes, this is one of the common commands */
			n++; /* use the entry from common_cmds[] */
			if (!prefixcmp(candidate, cmd)) {
				/* Give prefix match a very good score */
				main_cmds.names[i]->len = 0;
				continue;
			}
		}

		main_cmds.names[i]->len =
			levenshtein(cmd, candidate, 0, 2, 1, 4) + 1;
	}

	qsort(main_cmds.names, main_cmds.cnt,
	      sizeof(*main_cmds.names), levenshtein_compare);

	if (!main_cmds.cnt)
		die ("Uh oh. Your system reports no Git commands at all.");

	/* skip and count prefix matches */
	for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
		; /* still counting */

	if (main_cmds.cnt <= n) {
		/* prefix matches with everything? that is too ambiguous */
		best_similarity = SIMILARITY_FLOOR + 1;
	} else {
		/* count all the most similar ones */
		for (best_similarity = main_cmds.names[n++]->len;
		     (n < main_cmds.cnt &&
		      best_similarity == main_cmds.names[n]->len);
		     n++)
			; /* still counting */
	}
	if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
		const char *assumed = main_cmds.names[0]->name;
		main_cmds.names[0] = NULL;
		clean_cmdnames(&main_cmds);
		fprintf(stderr, "WARNING: You called a Git command named '%s', "
			"which does not exist.\n"
			"Continuing under the assumption that you meant '%s'\n",
			cmd, assumed);
		if (autocorrect > 0) {
			fprintf(stderr, "in %0.1f seconds automatically...\n",
				(float)autocorrect/10.0);
			poll(NULL, 0, autocorrect * 100);
		}
		return assumed;
	}

	fprintf(stderr, "git: '%s' is not a git command. See 'git --help'.\n", cmd);

	if (SIMILAR_ENOUGH(best_similarity)) {
		fprintf(stderr, "\nDid you mean %s?\n",
			n < 2 ? "this": "one of these");

		for (i = 0; i < n; i++)
			fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
	}

	exit(1);
}

int cmd_version(int argc, const char **argv, const char *prefix)
{
	printf("git version %s\n", git_version_string);
	return 0;
}
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