Merge branch 'js/symlink'

* js/symlink:
  Tell multi-parent diff about core.symlinks.
  Handle core.symlinks=false case in merge-recursive.
  Add core.symlinks to mark filesystems that do not support symbolic links.

15 files changed, 175 insertions, 13 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index d20902bc33..5408dd67d3 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -117,6 +117,13 @@ core.fileMode::
 	the working copy are ignored; useful on broken filesystems like FAT.
 	See gitlink:git-update-index[1]. True by default.
 
+core.symlinks::
+	If false, symbolic links are checked out as small plain files that
+	contain the link text. gitlink:git-update-index[1] and
+	gitlink:git-add[1] will not change the recorded type to regular
+	file. Useful on filesystems like FAT that do not support
+	symbolic links. True by default.
+
 core.gitProxy::
 	A "proxy command" to execute (as 'command host port') instead
 	of establishing direct connection to the remote server when
diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
index b161c8b32b..cd5e014d48 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -295,6 +295,11 @@ in the index and the file mode on the filesystem if they differ only on
 executable bit.   On such an unfortunate filesystem, you may
 need to use `git-update-index --chmod=`.
 
+Quite similarly, if `core.symlinks` configuration variable is set
+to 'false' (see gitlink:git-config[1]), symbolic links are checked out
+as plain files, and this command does not modify a recorded file mode
+from symbolic link to regular file.
+
 The command looks at `core.ignorestat` configuration variable.  See
 'Using "assume unchanged" bit' section above.
 
diff --git a/builtin-apply.c b/builtin-apply.c
index 38f647510a..53935109a3 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -2359,7 +2359,7 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
 	char *nbuf;
 	unsigned long nsize;
 
-	if (S_ISLNK(mode))
+	if (has_symlinks && S_ISLNK(mode))
 		/* Although buf:size is counted string, it also is NUL
 		 * terminated.
 		 */
diff --git a/builtin-update-index.c b/builtin-update-index.c
index 65246dad8d..71cef633c0 100644
--- a/builtin-update-index.c
+++ b/builtin-update-index.c
@@ -109,11 +109,11 @@ static int add_file_to_cache(const char *path)
 	ce->ce_flags = htons(namelen);
 	fill_stat_cache_info(ce, &st);
 
-	if (trust_executable_bit)
+	if (trust_executable_bit && has_symlinks)
 		ce->ce_mode = create_ce_mode(st.st_mode);
 	else {
-		/* If there is an existing entry, pick the mode bits
-		 * from it, otherwise assume unexecutable.
+		/* If there is an existing entry, pick the mode bits and type
+		 * from it, otherwise assume unexecutable regular file.
 		 */
 		struct cache_entry *ent;
 		int pos = cache_name_pos(path, namelen);
diff --git a/cache.h b/cache.h
index 8018b2cd3b..c291163e6d 100644
--- a/cache.h
+++ b/cache.h
@@ -108,7 +108,10 @@ static inline unsigned int create_ce_mode(unsigned int mode)
 }
 static inline unsigned int ce_mode_from_stat(struct cache_entry *ce, unsigned int mode)
 {
-	extern int trust_executable_bit;
+	extern int trust_executable_bit, has_symlinks;
+	if (!has_symlinks && S_ISREG(mode) &&
+	    ce && S_ISLNK(ntohl(ce->ce_mode)))
+		return ce->ce_mode;
 	if (!trust_executable_bit && S_ISREG(mode)) {
 		if (ce && S_ISREG(ntohl(ce->ce_mode)))
 			return ce->ce_mode;
@@ -215,6 +218,7 @@ extern int delete_ref(const char *, unsigned char *sha1);
 /* Environment bits from configuration mechanism */
 extern int use_legacy_headers;
 extern int trust_executable_bit;
+extern int has_symlinks;
 extern int assume_unchanged;
 extern int prefer_symlink_refs;
 extern int log_all_ref_updates;
diff --git a/combine-diff.c b/combine-diff.c
index 9daa0cb9a9..6d928f282a 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -699,8 +699,18 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 			 !fstat(fd, &st)) {
 			size_t len = st.st_size;
 			size_t sz = 0;
+			int is_file, i;
 
 			elem->mode = canon_mode(st.st_mode);
+			/* if symlinks don't work, assume symlink if all parents
+			 * are symlinks
+			 */
+			is_file = has_symlinks;
+			for (i = 0; !is_file && i < num_parent; i++)
+				is_file = !S_ISLNK(elem->parent[i].mode);
+			if (!is_file)
+				elem->mode = canon_mode(S_IFLNK);
+
 			result_size = len;
 			result = xmalloc(len + 1);
 			while (sz < len) {
diff --git a/config.c b/config.c
index 0ff413b804..7ac3947858 100644
--- a/config.c
+++ b/config.c
@@ -269,6 +269,11 @@ int git_default_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.symlinks")) {
+		has_symlinks = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp(var, "core.bare")) {
 		is_bare_repository_cfg = git_config_bool(var, value);
 		return 0;
diff --git a/diff-lib.c b/diff-lib.c
index 88e59b5794..778cf58244 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -412,6 +412,9 @@ int run_diff_files(struct rev_info *revs, int silent_on_removed)
 		    S_ISREG(newmode) && S_ISREG(oldmode) &&
 		    ((newmode ^ oldmode) == 0111))
 			newmode = oldmode;
+		else if (!has_symlinks &&
+		    S_ISREG(newmode) && S_ISLNK(oldmode))
+			newmode = oldmode;
 		diff_change(&revs->diffopt, oldmode, newmode,
 			    ce->sha1, (changed ? null_sha1 : ce->sha1),
 			    ce->name, NULL);
diff --git a/entry.c b/entry.c
index 21b5f2e26d..d72f811580 100644
--- a/entry.c
+++ b/entry.c
@@ -111,9 +111,12 @@ static int write_entry(struct cache_entry *ce, char *path, struct checkout *stat
 			return error("git-checkout-index: unable to write file %s", path);
 		break;
 	case S_IFLNK:
-		if (to_tempfile) {
-			strcpy(path, ".merge_link_XXXXXX");
-			fd = mkstemp(path);
+		if (to_tempfile || !has_symlinks) {
+			if (to_tempfile) {
+				strcpy(path, ".merge_link_XXXXXX");
+				fd = mkstemp(path);
+			} else
+				fd = create_file(path, 0666);
 			if (fd < 0) {
 				free(new);
 				return error("git-checkout-index: unable to create "
diff --git a/environment.c b/environment.c
index 570e32ac3c..49486dd9f1 100644
--- a/environment.c
+++ b/environment.c
@@ -13,6 +13,7 @@ char git_default_email[MAX_GITNAME];
 char git_default_name[MAX_GITNAME];
 int use_legacy_headers = 1;
 int trust_executable_bit = 1;
+int has_symlinks = 1;
 int assume_unchanged;
 int prefer_symlink_refs;
 int is_bare_repository_cfg = -1; /* unspecified */
diff --git a/merge-recursive.c b/merge-recursive.c
index 87cd8709bb..c96e1a734c 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -570,7 +570,7 @@ static void update_file_flags(const unsigned char *sha,
 		if (type != OBJ_BLOB)
 			die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 
-		if (S_ISREG(mode)) {
+		if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 			int fd;
 			if (mkdir_p(path, 0777))
 				die("failed to create path %s: %s", path, strerror(errno));
@@ -591,6 +591,7 @@ static void update_file_flags(const unsigned char *sha,
 			mkdir_p(path, 0777);
 			unlink(path);
 			symlink(lnk, path);
+			free(lnk);
 		} else
 			die("do not know what to do with %06o %s '%s'",
 			    mode, sha1_to_hex(sha), path);
diff --git a/read-cache.c b/read-cache.c
index 7a104e3512..4a972b4ab7 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -125,7 +125,9 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
 			changed |= MODE_CHANGED;
 		break;
 	case S_IFLNK:
-		changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0;
+		if (!S_ISLNK(st->st_mode) &&
+		    (has_symlinks || !S_ISREG(st->st_mode)))
+			changed |= TYPE_CHANGED;
 		break;
 	default:
 		die("internal error: ce_mode is %o", ntohl(ce->ce_mode));
@@ -344,11 +346,11 @@ int add_file_to_index(const char *path, int verbose)
 	ce->ce_flags = htons(namelen);
 	fill_stat_cache_info(ce, &st);
 
-	if (trust_executable_bit)
+	if (trust_executable_bit && has_symlinks)
 		ce->ce_mode = create_ce_mode(st.st_mode);
 	else {
-		/* If there is an existing entry, pick the mode bits
-		 * from it, otherwise assume unexecutable.
+		/* If there is an existing entry, pick the mode bits and type
+		 * from it, otherwise assume unexecutable regular file.
 		 */
 		struct cache_entry *ent;
 		int pos = cache_name_pos(path, namelen);
diff --git a/t/t2005-checkout-index-symlinks.sh b/t/t2005-checkout-index-symlinks.sh
new file mode 100755
index 0000000000..e34a515333
--- /dev/null
+++ b/t/t2005-checkout-index-symlinks.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+#
+# Copyright (c) 2007 Johannes Sixt
+#
+
+test_description='git-checkout-index on filesystem w/o symlinks test.
+
+This tests that git-checkout-index creates a symbolic link as a plain
+file if core.symlinks is false.'
+
+. ./test-lib.sh
+
+test_expect_success \
+'preparation' '
+git-config core.symlinks false &&
+l=$(echo -n file | git-hash-object -t blob -w --stdin) &&
+echo "120000 $l	symlink" | git-update-index --index-info'
+
+test_expect_success \
+'the checked-out symlink must be a file' '
+git-checkout-index symlink &&
+test -f symlink'
+
+test_expect_success \
+'the file must be the blob we added during the setup' '
+test "$(git-hash-object -t blob symlink)" = $l'
+
+test_done
diff --git a/t/t2102-update-index-symlinks.sh b/t/t2102-update-index-symlinks.sh
new file mode 100755
index 0000000000..969ef891d3
--- /dev/null
+++ b/t/t2102-update-index-symlinks.sh
@@ -0,0 +1,31 @@
+#!/bin/sh
+#
+# Copyright (c) 2007 Johannes Sixt
+#
+
+test_description='git-update-index on filesystem w/o symlinks test.
+
+This tests that git-update-index keeps the symbolic link property
+even if a plain file is in the working tree if core.symlinks is false.'
+
+. ./test-lib.sh
+
+test_expect_success \
+'preparation' '
+git-config core.symlinks false &&
+l=$(echo -n file | git-hash-object -t blob -w --stdin) &&
+echo "120000 $l	symlink" | git-update-index --index-info'
+
+test_expect_success \
+'modify the symbolic link' '
+echo -n new-file > symlink &&
+git-update-index symlink'
+
+test_expect_success \
+'the index entry must still be a symbolic link' '
+case "`git-ls-files --stage --cached symlink`" in
+120000" "*symlink) echo ok;;
+*) echo fail; git-ls-files --stage --cached symlink; (exit 1);;
+esac'
+
+test_done
diff --git a/t/t6025-merge-symlinks.sh b/t/t6025-merge-symlinks.sh
new file mode 100644
index 0000000000..3c1a6972bd
--- /dev/null
+++ b/t/t6025-merge-symlinks.sh
@@ -0,0 +1,62 @@
+#!/bin/sh
+#
+# Copyright (c) 2007 Johannes Sixt
+#
+
+test_description='merging symlinks on filesystem w/o symlink support.
+
+This tests that git-merge-recursive writes merge results as plain files
+if core.symlinks is false.'
+
+. ./test-lib.sh
+
+test_expect_success \
+'setup' '
+git-config core.symlinks false &&
+> file &&
+git-add file &&
+git-commit -m initial &&
+git-branch b-symlink &&
+git-branch b-file &&
+l=$(echo -n file | git-hash-object -t blob -w --stdin) &&
+echo "120000 $l	symlink" | git-update-index --index-info &&
+git-commit -m master &&
+git-checkout b-symlink &&
+l=$(echo -n file-different | git-hash-object -t blob -w --stdin) &&
+echo "120000 $l	symlink" | git-update-index --index-info &&
+git-commit -m b-symlink &&
+git-checkout b-file &&
+echo plain-file > symlink &&
+git-add symlink &&
+git-commit -m b-file'
+
+test_expect_failure \
+'merge master into b-symlink, which has a different symbolic link' '
+! git-checkout b-symlink ||
+git-merge master'
+
+test_expect_success \
+'the merge result must be a file' '
+test -f symlink'
+
+test_expect_failure \
+'merge master into b-file, which has a file instead of a symbolic link' '
+! (git-reset --hard &&
+git-checkout b-file) ||
+git-merge master'
+
+test_expect_success \
+'the merge result must be a file' '
+test -f symlink'
+
+test_expect_failure \
+'merge b-file, which has a file instead of a symbolic link, into master' '
+! (git-reset --hard &&
+git-checkout master) ||
+git-merge b-file'
+
+test_expect_success \
+'the merge result must be a file' '
+test -f symlink'
+
+test_done