diff --git a/Documentation/gitattributes.adoc b/Documentation/gitattributes.adoc index 7eaca899725664..26f80c3775a474 100644 --- a/Documentation/gitattributes.adoc +++ b/Documentation/gitattributes.adoc @@ -403,6 +403,36 @@ sign `$` upon checkout. Any byte sequence that begins with with `$Id$` upon check-in. +`symlink` +^^^^^^^^^ + +On Windows, symbolic links have a type: a "file symlink" must point at +a file, and a "directory symlink" must point at a directory. If the +type of symlink does not match its target, it doesn't work. + +Git does not record the type of symlink in the index or in a tree. On +checkout it'll guess the type, which only works if the target exists +at the time the symlink is created. This may often not be the case, +for example when the link points at a directory inside a submodule. + +The `symlink` attribute allows you to explicitly set the type of symlink +to `file` or `dir`, so Git doesn't have to guess. If you have a set of +symlinks that point at other files, you can do: + +------------------------ +*.gif symlink=file +------------------------ + +To tell Git that a symlink points at a directory, use: + +------------------------ +tools_folder symlink=dir +------------------------ + +The `symlink` attribute is ignored on platforms other than Windows, +since they don't distinguish between different types of symlinks. + + `filter` ^^^^^^^^ diff --git a/apply.c b/apply.c index b124678b93bd93..6f74abb4624e4d 100644 --- a/apply.c +++ b/apply.c @@ -4398,7 +4398,7 @@ static int try_create_file(struct apply_state *state, const char *path, /* Although buf:size is counted string, it also is NUL * terminated. */ - return !!symlink(buf, path); + return !!create_symlink(state && state->repo ? state->repo->index : NULL, buf, path); fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666); if (fd < 0) diff --git a/builtin/difftool.c b/builtin/difftool.c index 41cd00066cc58a..7aca022ee31df2 100644 --- a/builtin/difftool.c +++ b/builtin/difftool.c @@ -541,7 +541,7 @@ static int run_dir_diff(struct repository *repo, } add_path(&wtdir, wtdir_len, dst_path); if (dt_options->symlinks) { - if (symlink(wtdir.buf, rdir.buf)) { + if (create_symlink(lstate.istate, wtdir.buf, rdir.buf)) { ret = error_errno("could not symlink '%s' to '%s'", wtdir.buf, rdir.buf); goto finish; } diff --git a/compat/mingw.c b/compat/mingw.c index c00e18e37aa802..17cce65cce1d89 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -25,6 +25,7 @@ #include "../write-or-die.h" #include "../repository.h" #include "win32/fscache.h" +#include "../attr.h" #define HCAST(type, handle) ((type)(intptr_t)handle) @@ -461,6 +462,54 @@ static void process_phantom_symlinks(void) LeaveCriticalSection(&phantom_symlinks_cs); } +static int create_phantom_symlink(wchar_t *wtarget, wchar_t *wlink) +{ + int len; + + /* create file symlink */ + if (!CreateSymbolicLinkW(wlink, wtarget, symlink_file_flags)) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + + /* convert to directory symlink if target exists */ + switch (process_phantom_symlink(wtarget, wlink)) { + case PHANTOM_SYMLINK_RETRY: { + /* if target doesn't exist, add to phantom symlinks list */ + wchar_t wfullpath[MAX_LONG_PATH]; + struct phantom_symlink_info *psi; + + /* convert to absolute path to be independent of cwd */ + len = GetFullPathNameW(wlink, MAX_LONG_PATH, wfullpath, NULL); + if (!len || len >= MAX_LONG_PATH) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + + /* over-allocate and fill phantom_symlink_info structure */ + psi = xmalloc(sizeof(struct phantom_symlink_info) + + sizeof(wchar_t) * (len + wcslen(wtarget) + 2)); + psi->wlink = (wchar_t *)(psi + 1); + wcscpy(psi->wlink, wfullpath); + psi->wtarget = psi->wlink + len + 1; + wcscpy(psi->wtarget, wtarget); + + EnterCriticalSection(&phantom_symlinks_cs); + psi->next = phantom_symlinks; + phantom_symlinks = psi; + LeaveCriticalSection(&phantom_symlinks_cs); + break; + } + case PHANTOM_SYMLINK_DIRECTORY: + /* if we created a dir symlink, process other phantom symlinks */ + process_phantom_symlinks(); + break; + default: + break; + } + return 0; +} + /* Normalizes NT paths as returned by some low-level APIs. */ static wchar_t *normalize_ntpath(wchar_t *wbuf) { @@ -3153,7 +3202,38 @@ int link(const char *oldpath, const char *newpath) return 0; } -int symlink(const char *target, const char *link) +enum symlink_type { + SYMLINK_TYPE_UNSPECIFIED = 0, + SYMLINK_TYPE_FILE, + SYMLINK_TYPE_DIRECTORY, +}; + +static enum symlink_type check_symlink_attr(struct index_state *index, const char *link) +{ + static struct attr_check *check; + const char *value; + + if (!index) + return SYMLINK_TYPE_UNSPECIFIED; + + if (!check) + check = attr_check_initl("symlink", NULL); + + git_check_attr(index, link, check); + + value = check->items[0].value; + if (ATTR_UNSET(value)) + return SYMLINK_TYPE_UNSPECIFIED; + if (!strcmp(value, "file")) + return SYMLINK_TYPE_FILE; + if (!strcmp(value, "dir") || !strcmp(value, "directory")) + return SYMLINK_TYPE_DIRECTORY; + + warning(_("ignoring invalid symlink type '%s' for '%s'"), value, link); + return SYMLINK_TYPE_UNSPECIFIED; +} + +int mingw_create_symlink(struct index_state *index, const char *target, const char *link) { wchar_t wtarget[MAX_LONG_PATH], wlink[MAX_LONG_PATH]; int len; @@ -3173,48 +3253,31 @@ int symlink(const char *target, const char *link) if (wtarget[len] == '/') wtarget[len] = '\\'; - /* create file symlink */ - if (!CreateSymbolicLinkW(wlink, wtarget, symlink_file_flags)) { - errno = err_win_to_posix(GetLastError()); - return -1; - } - - /* convert to directory symlink if target exists */ - switch (process_phantom_symlink(wtarget, wlink)) { - case PHANTOM_SYMLINK_RETRY: { - /* if target doesn't exist, add to phantom symlinks list */ - wchar_t wfullpath[MAX_LONG_PATH]; - struct phantom_symlink_info *psi; - - /* convert to absolute path to be independent of cwd */ - len = GetFullPathNameW(wlink, MAX_LONG_PATH, wfullpath, NULL); - if (!len || len >= MAX_LONG_PATH) { - errno = err_win_to_posix(GetLastError()); - return -1; - } - - /* over-allocate and fill phantom_symlink_info structure */ - psi = xmalloc(sizeof(struct phantom_symlink_info) - + sizeof(wchar_t) * (len + wcslen(wtarget) + 2)); - psi->wlink = (wchar_t *)(psi + 1); - wcscpy(psi->wlink, wfullpath); - psi->wtarget = psi->wlink + len + 1; - wcscpy(psi->wtarget, wtarget); - - EnterCriticalSection(&phantom_symlinks_cs); - psi->next = phantom_symlinks; - phantom_symlinks = psi; - LeaveCriticalSection(&phantom_symlinks_cs); - break; - } - case PHANTOM_SYMLINK_DIRECTORY: - /* if we created a dir symlink, process other phantom symlinks */ + switch (check_symlink_attr(index, link)) { + case SYMLINK_TYPE_UNSPECIFIED: + /* Create a phantom symlink: it is initially created as a file + * symlink, but may change to a directory symlink later if/when + * the target exists. */ + return create_phantom_symlink(wtarget, wlink); + case SYMLINK_TYPE_FILE: + if (!CreateSymbolicLinkW(wlink, wtarget, symlink_file_flags)) + break; + return 0; + case SYMLINK_TYPE_DIRECTORY: + if (!CreateSymbolicLinkW(wlink, wtarget, + symlink_directory_flags)) + break; + /* There may be dangling phantom symlinks that point at this + * one, which should now morph into directory symlinks. */ process_phantom_symlinks(); - break; + return 0; default: - break; + BUG("unhandled symlink type"); } - return 0; + + /* CreateSymbolicLinkW failed. */ + errno = err_win_to_posix(GetLastError()); + return -1; } #ifndef _WINNT_H diff --git a/compat/mingw.h b/compat/mingw.h index ccb474021fa57e..b6f00b539aef9c 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -218,8 +218,10 @@ int setitimer(int type, struct itimerval *in, struct itimerval *out); int sigaction(int sig, struct sigaction *in, struct sigaction *out); int link(const char *oldpath, const char *newpath); int uname(struct utsname *buf); -int symlink(const char *target, const char *link); int readlink(const char *path, char *buf, size_t bufsiz); +struct index_state; +int mingw_create_symlink(struct index_state *index, const char *target, const char *link); +#define create_symlink mingw_create_symlink /* * replacements of existing functions diff --git a/entry.c b/entry.c index b5106fd5d5f189..3e4f47640312c2 100644 --- a/entry.c +++ b/entry.c @@ -324,7 +324,7 @@ static int write_entry(struct cache_entry *ce, char *path, struct conv_attrs *ca if (!has_symlinks || to_tempfile) goto write_file_entry; - ret = symlink(new_blob, path); + ret = create_symlink(state->istate, new_blob, path); free(new_blob); if (ret) return error_errno("unable to create symlink %s", path); diff --git a/git-compat-util.h b/git-compat-util.h index 09a5018ee5b0f5..7f47f819bf13cf 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -651,6 +651,16 @@ static inline int git_has_dir_sep(const char *path) #define is_mount_point is_mount_point_via_stat #endif +#ifndef create_symlink +struct index_state; +static inline int git_create_symlink(struct index_state *index UNUSED, + const char *target, const char *link) +{ + return symlink(target, link); +} +#define create_symlink git_create_symlink +#endif + #ifndef query_user_email #define query_user_email() NULL #endif diff --git a/merge-recursive.c b/merge-recursive.c index 5dfaf32b2c1880..39b3c479c69af7 100644 --- a/merge-recursive.c +++ b/merge-recursive.c @@ -1005,7 +1005,7 @@ static int update_file_flags(struct merge_options *opt, char *lnk = xmemdupz(buf, size); safe_create_leading_directories_const(path); unlink(path); - if (symlink(lnk, path)) + if (create_symlink(&opt->priv->orig_index, lnk, path)) ret = err(opt, _("failed to symlink '%s': %s"), path, strerror(errno)); free(lnk); diff --git a/refs/files-backend.c b/refs/files-backend.c index 29f08dced40418..09f3969327108b 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -2044,7 +2044,7 @@ static int create_ref_symlink(struct ref_lock *lock, const char *target) char *ref_path = get_locked_file_path(&lock->lk); unlink(ref_path); - ret = symlink(target, ref_path); + ret = create_symlink(NULL, target, ref_path); free(ref_path); if (ret) diff --git a/setup.c b/setup.c index d96de2a34ec2e9..715b0de22ae399 100644 --- a/setup.c +++ b/setup.c @@ -2135,7 +2135,7 @@ static void copy_templates_1(struct strbuf *path, struct strbuf *template_path, if (strbuf_readlink(&lnk, template_path->buf, st_template.st_size) < 0) die_errno(_("cannot readlink '%s'"), template_path->buf); - if (symlink(lnk.buf, path->buf)) + if (create_symlink(NULL, lnk.buf, path->buf)) die_errno(_("cannot symlink '%s' '%s'"), lnk.buf, path->buf); strbuf_release(&lnk); @@ -2396,7 +2396,7 @@ static int create_default_files(const char *template_path, path = git_path_buf(&buf, "tXXXXXX"); if (!close(xmkstemp(path)) && !unlink(path) && - !symlink("testing", path) && + !create_symlink(NULL, "testing", path) && !lstat(path, &st1) && S_ISLNK(st1.st_mode)) unlink(path); /* good */ diff --git a/t/meson.build b/t/meson.build index af4b8be28740be..97a9b7c160b5a2 100644 --- a/t/meson.build +++ b/t/meson.build @@ -276,6 +276,7 @@ integration_tests = [ 't2027-checkout-track.sh', 't2030-unresolve-info.sh', 't2031-checkout-long-paths.sh', + 't2040-checkout-symlink-attr.sh', 't2050-git-dir-relative.sh', 't2060-switch.sh', 't2070-restore.sh', diff --git a/t/t2040-checkout-symlink-attr.sh b/t/t2040-checkout-symlink-attr.sh new file mode 100755 index 00000000000000..e00c31d096ce88 --- /dev/null +++ b/t/t2040-checkout-symlink-attr.sh @@ -0,0 +1,46 @@ +#!/bin/sh + +test_description='checkout symlinks with `symlink` attribute on Windows + +Ensures that Git for Windows creates symlinks of the right type, +as specified by the `symlink` attribute in `.gitattributes`.' + +# Tell MSYS to create native symlinks. Without this flag test-lib's +# prerequisite detection for SYMLINKS doesn't detect the right thing. +MSYS=winsymlinks:nativestrict && export MSYS + +. ./test-lib.sh + +if ! test_have_prereq MINGW,SYMLINKS +then + skip_all='skipping $0: MinGW-only test, which requires symlink support.' + test_done +fi + +# Adds a symlink to the index without clobbering the work tree. +cache_symlink () { + sha=$(printf '%s' "$1" | git hash-object --stdin -w) && + git update-index --add --cacheinfo 120000,$sha,"$2" +} + +test_expect_success 'checkout symlinks with attr' ' + cache_symlink file1 file-link && + cache_symlink dir dir-link && + + printf "file-link symlink=file\ndir-link symlink=dir\n" >.gitattributes && + git add .gitattributes && + + git checkout . && + + mkdir dir && + echo "[a]b=c" >file1 && + echo "[x]y=z" >dir/file2 && + + # MSYS2 is very forgiving, it will resolve symlinks even if the + # symlink type is incorrect. To make this test meaningful, try + # them with a native, non-MSYS executable, such as `git config`. + test "$(git config -f file-link a.b)" = "c" && + test "$(git config -f dir-link/file2 x.y)" = "z" +' + +test_done