Revision 6aba117d5cf7128e7bc942888263552fe927e13f authored by Elijah Newren on 29 August 2018, 07:06:13 UTC, committed by Junio C Hamano on 30 August 2018, 14:58:59 UTC
Let's say you have the following three trees, where Base is from one commit
behind either master or branch:

   Base  : bar_v1, foo/{file1, file2, file3}
   branch: bar_v2, foo/{file1, file2},       goo/file3
   master: bar_v3, foo/{file1, file2, file3}

Using git-am (or am-based rebase) to apply the changes from branch onto
master results in the following tree:

   Result: bar_merged, goo/{file1, file2, file3}

This is not what users want; they did not rename foo/ -> goo/, they only
renamed one file within that directory.  The reason this happens is am
constructs fake trees (via build_fake_ancestor()) of the following form:

   Base_bfa  : bar_v1, foo/file3
   branch_bfa: bar_v2, goo/file3

Combining these two trees with master's tree:

   master: bar_v3, foo/{file1, file2, file3},

You can see that merge_recursive_generic() would see branch_bfa as renaming
foo/ -> goo/, and master as just adding both foo/file1 and foo/file2.  As
such, it ends up with goo/{file1, file2, file3}

The core problem is that am does not have access to the original trees; it
can only construct trees using the blobs involved in the patch.  As such,
it is not safe to perform directory rename detection within am -3.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 5fdddd9
Raw File
quote.h
#ifndef QUOTE_H
#define QUOTE_H

struct strbuf;

/* Help to copy the thing properly quoted for the shell safety.
 * any single quote is replaced with '\'', any exclamation point
 * is replaced with '\!', and the whole thing is enclosed in a
 * single quote pair.
 *
 * For example, if you are passing the result to system() as an
 * argument:
 *
 * sprintf(cmd, "foobar %s %s", sq_quote(arg0), sq_quote(arg1))
 *
 * would be appropriate.  If the system() is going to call ssh to
 * run the command on the other side:
 *
 * sprintf(cmd, "git-diff-tree %s %s", sq_quote(arg0), sq_quote(arg1));
 * sprintf(rcmd, "ssh %s %s", sq_quote(host), sq_quote(cmd));
 *
 * Note that the above examples leak memory!  Remember to free result from
 * sq_quote() in a real application.
 *
 * sq_quote_buf() writes to an existing buffer of specified size; it
 * will return the number of characters that would have been written
 * excluding the final null regardless of the buffer size.
 *
 * sq_quotef() quotes the entire formatted string as a single result.
 */

extern void sq_quote_buf(struct strbuf *, const char *src);
extern void sq_quote_argv(struct strbuf *, const char **argv);
extern void sq_quotef(struct strbuf *, const char *fmt, ...);

/*
 * These match their non-pretty variants, except that they avoid
 * quoting when there are no exotic characters. These should only be used for
 * human-readable output, as sq_dequote() is not smart enough to dequote it.
 */
void sq_quote_buf_pretty(struct strbuf *, const char *src);
void sq_quote_argv_pretty(struct strbuf *, const char **argv);

/* This unwraps what sq_quote() produces in place, but returns
 * NULL if the input does not look like what sq_quote would have
 * produced.
 */
extern char *sq_dequote(char *);

/*
 * Same as the above, but can be used to unwrap many arguments in the
 * same string separated by space. Like sq_quote, it works in place,
 * modifying arg and appending pointers into it to argv.
 */
extern int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc);

/*
 * Same as above, but store the unquoted strings in an argv_array. We will
 * still modify arg in place, but unlike sq_dequote_to_argv, the argv_array
 * will duplicate and take ownership of the strings.
 */
struct argv_array;
extern int sq_dequote_to_argv_array(char *arg, struct argv_array *);

extern int unquote_c_style(struct strbuf *, const char *quoted, const char **endp);
extern size_t quote_c_style(const char *name, struct strbuf *, FILE *, int no_dq);
extern void quote_two_c_style(struct strbuf *, const char *, const char *, int);

extern void write_name_quoted(const char *name, FILE *, int terminator);
extern void write_name_quoted_relative(const char *name, const char *prefix,
		FILE *fp, int terminator);

/* quote path as relative to the given prefix */
extern char *quote_path_relative(const char *in, const char *prefix,
			  struct strbuf *out);

/* quoting as a string literal for other languages */
extern void perl_quote_buf(struct strbuf *sb, const char *src);
extern void python_quote_buf(struct strbuf *sb, const char *src);
extern void tcl_quote_buf(struct strbuf *sb, const char *src);
extern void basic_regex_quote_buf(struct strbuf *sb, const char *src);

#endif
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