Merge branch 'jk/diff-blob'

The result from "git diff" that compares two blobs, e.g. "git diff
$commit1:$path $commit2:$path", used to be shown with the full
object name as given on the command line, but it is more natural to
use the $path in the output and use it to look up .gitattributes.

* jk/diff-blob:
  diff: use blob path for blob/file diffs
  diff: use pending "path" if it is available
  diff: use the word "path" instead of "name" for blobs
  diff: pass whole pending entry in blobinfo
  handle_revision_arg: record paths for pending objects
  handle_revision_arg: record modes for "a..b" endpoints
  t4063: add tests of direct blob diffs
  get_sha1_with_context: dynamically allocate oc->path
  get_sha1_with_context: always initialize oc->symlink_path
  sha1_name: consistently refer to object_context as "oc"
  handle_revision_arg: add handle_dotdot() helper
  handle_revision_arg: hoist ".." check out of range parsing
  handle_revision_arg: stop using "dotdot" as a generic pointer
  handle_revision_arg: simplify commit reference lookups
  handle_revision_arg: reset "dotdot" consistently

10 files changed, 301 insertions, 147 deletions

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 9af863e..73c81f0 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -61,7 +61,8 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 	if (unknown_type)
 		flags |= LOOKUP_UNKNOWN_OBJECT;
 
-	if (get_sha1_with_context(obj_name, 0, oid.hash, &obj_context))
+	if (get_sha1_with_context(obj_name, GET_SHA1_RECORD_PATH,
+				  oid.hash, &obj_context))
 		die("Not a valid object name %s", obj_name);
 
 	if (!path)
@@ -166,6 +167,7 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 
 	write_or_die(1, buf, size);
 	free(buf);
+	free(obj_context.path);
 	return 0;
 }
 
diff --git a/builtin/diff.c b/builtin/diff.c
index 8c03dda..0c8f86e 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -20,23 +20,22 @@
 #define DIFF_NO_INDEX_EXPLICIT 1
 #define DIFF_NO_INDEX_IMPLICIT 2
 
-struct blobinfo {
-	struct object_id oid;
-	const char *name;
-	unsigned mode;
-};
-
 static const char builtin_diff_usage[] =
 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
 
+static const char *blob_path(struct object_array_entry *entry)
+{
+	return entry->path ? entry->path : entry->name;
+}
+
 static void stuff_change(struct diff_options *opt,
 			 unsigned old_mode, unsigned new_mode,
 			 const struct object_id *old_oid,
 			 const struct object_id *new_oid,
 			 int old_oid_valid,
 			 int new_oid_valid,
-			 const char *old_name,
-			 const char *new_name)
+			 const char *old_path,
+			 const char *new_path)
 {
 	struct diff_filespec *one, *two;
 
@@ -47,16 +46,16 @@ static void stuff_change(struct diff_options *opt,
 	if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
 		SWAP(old_mode, new_mode);
 		SWAP(old_oid, new_oid);
-		SWAP(old_name, new_name);
+		SWAP(old_path, new_path);
 	}
 
 	if (opt->prefix &&
-	    (strncmp(old_name, opt->prefix, opt->prefix_length) ||
-	     strncmp(new_name, opt->prefix, opt->prefix_length)))
+	    (strncmp(old_path, opt->prefix, opt->prefix_length) ||
+	     strncmp(new_path, opt->prefix, opt->prefix_length)))
 		return;
 
-	one = alloc_filespec(old_name);
-	two = alloc_filespec(new_name);
+	one = alloc_filespec(old_path);
+	two = alloc_filespec(new_path);
 	fill_filespec(one, old_oid->hash, old_oid_valid, old_mode);
 	fill_filespec(two, new_oid->hash, new_oid_valid, new_mode);
 
@@ -65,7 +64,7 @@ static void stuff_change(struct diff_options *opt,
 
 static int builtin_diff_b_f(struct rev_info *revs,
 			    int argc, const char **argv,
-			    struct blobinfo *blob)
+			    struct object_array_entry **blob)
 {
 	/* Blob vs file in the working tree*/
 	struct stat st;
@@ -84,14 +83,15 @@ static int builtin_diff_b_f(struct rev_info *revs,
 
 	diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
 
-	if (blob[0].mode == S_IFINVALID)
-		blob[0].mode = canon_mode(st.st_mode);
+	if (blob[0]->mode == S_IFINVALID)
+		blob[0]->mode = canon_mode(st.st_mode);
 
 	stuff_change(&revs->diffopt,
-		     blob[0].mode, canon_mode(st.st_mode),
-		     &blob[0].oid, &null_oid,
+		     blob[0]->mode, canon_mode(st.st_mode),
+		     &blob[0]->item->oid, &null_oid,
 		     1, 0,
-		     path, path);
+		     blob[0]->path ? blob[0]->path : path,
+		     path);
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
 	return 0;
@@ -99,24 +99,24 @@ static int builtin_diff_b_f(struct rev_info *revs,
 
 static int builtin_diff_blobs(struct rev_info *revs,
 			      int argc, const char **argv,
-			      struct blobinfo *blob)
+			      struct object_array_entry **blob)
 {
 	unsigned mode = canon_mode(S_IFREG | 0644);
 
 	if (argc > 1)
 		usage(builtin_diff_usage);
 
-	if (blob[0].mode == S_IFINVALID)
-		blob[0].mode = mode;
+	if (blob[0]->mode == S_IFINVALID)
+		blob[0]->mode = mode;
 
-	if (blob[1].mode == S_IFINVALID)
-		blob[1].mode = mode;
+	if (blob[1]->mode == S_IFINVALID)
+		blob[1]->mode = mode;
 
 	stuff_change(&revs->diffopt,
-		     blob[0].mode, blob[1].mode,
-		     &blob[0].oid, &blob[1].oid,
+		     blob[0]->mode, blob[1]->mode,
+		     &blob[0]->item->oid, &blob[1]->item->oid,
 		     1, 1,
-		     blob[0].name, blob[1].name);
+		     blob_path(blob[0]), blob_path(blob[1]));
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);
 	return 0;
@@ -259,7 +259,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 	struct rev_info rev;
 	struct object_array ent = OBJECT_ARRAY_INIT;
 	int blobs = 0, paths = 0;
-	struct blobinfo blob[2];
+	struct object_array_entry *blob[2];
 	int nongit = 0, no_index = 0;
 	int result = 0;
 
@@ -408,9 +408,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 		} else if (obj->type == OBJ_BLOB) {
 			if (2 <= blobs)
 				die(_("more than two blobs given: '%s'"), name);
-			oidcpy(&blob[blobs].oid, &obj->oid);
-			blob[blobs].name = name;
-			blob[blobs].mode = entry->mode;
+			blob[blobs] = entry;
 			blobs++;
 
 		} else {
diff --git a/builtin/grep.c b/builtin/grep.c
index c6c26e9..72a1969 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -1190,7 +1190,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			break;
 		}
 
-		if (get_sha1_with_context(arg, 0, oid.hash, &oc)) {
+		if (get_sha1_with_context(arg, GET_SHA1_RECORD_PATH,
+					  oid.hash, &oc)) {
 			if (seen_dashdash)
 				die(_("unable to resolve revision: %s"), arg);
 			break;
@@ -1200,6 +1201,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 		if (!seen_dashdash)
 			verify_non_filename(prefix, arg);
 		add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
+		free(oc.path);
 	}
 
 	/*
diff --git a/builtin/log.c b/builtin/log.c
index a440601ef..e89ec94 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -483,16 +483,20 @@ static int show_blob_object(const struct object_id *oid, struct rev_info *rev, c
 	    !DIFF_OPT_TST(&rev->diffopt, ALLOW_TEXTCONV))
 		return stream_blob_to_fd(1, oid, NULL, 0);
 
-	if (get_sha1_with_context(obj_name, 0, oidc.hash, &obj_context))
+	if (get_sha1_with_context(obj_name, GET_SHA1_RECORD_PATH,
+				  oidc.hash, &obj_context))
 		die(_("Not a valid object name %s"), obj_name);
-	if (!obj_context.path[0] ||
-	    !textconv_object(obj_context.path, obj_context.mode, &oidc, 1, &buf, &size))
+	if (!obj_context.path ||
+	    !textconv_object(obj_context.path, obj_context.mode, &oidc, 1, &buf, &size)) {
+		free(obj_context.path);
 		return stream_blob_to_fd(1, oid, NULL, 0);
+	}
 
 	if (!buf)
 		die(_("git show %s: bad file"), obj_name);
 
 	write_or_die(1, buf, size);
+	free(obj_context.path);
 	return 0;
 }
 
diff --git a/cache.h b/cache.h
index ae4c45d..4d92aae 100644
--- a/cache.h
+++ b/cache.h
@@ -1334,13 +1334,18 @@ static inline int hex2chr(const char *s)
 
 struct object_context {
 	unsigned char tree[20];
-	char path[PATH_MAX];
 	unsigned mode;
 	/*
 	 * symlink_path is only used by get_tree_entry_follow_symlinks,
 	 * and only for symlinks that point outside the repository.
 	 */
 	struct strbuf symlink_path;
+	/*
+	 * If GET_SHA1_RECORD_PATH is set, this will record path (if any)
+	 * found when resolving the name. The caller is responsible for
+	 * releasing the memory.
+	 */
+	char *path;
 };
 
 #define GET_SHA1_QUIETLY           01
@@ -1350,6 +1355,7 @@ struct object_context {
 #define GET_SHA1_TREEISH          020
 #define GET_SHA1_BLOB             040
 #define GET_SHA1_FOLLOW_SYMLINKS 0100
+#define GET_SHA1_RECORD_PATH     0200
 #define GET_SHA1_ONLY_TO_DIE    04000
 
 #define GET_SHA1_DISAMBIGUATORS \
@@ -1364,7 +1370,7 @@ extern int get_sha1_tree(const char *str, unsigned char *sha1);
 extern int get_sha1_treeish(const char *str, unsigned char *sha1);
 extern int get_sha1_blob(const char *str, unsigned char *sha1);
 extern void maybe_die_on_misspelt_object_name(const char *name, const char *prefix);
-extern int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc);
+extern int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *oc);
 
 extern int get_oid(const char *str, struct object_id *oid);
 
diff --git a/revision.c b/revision.c
index b023945..3680a43 100644
--- a/revision.c
+++ b/revision.c
@@ -1429,134 +1429,168 @@ static void prepare_show_merge(struct rev_info *revs)
 	revs->limited = 1;
 }
 
+static int dotdot_missing(const char *arg, char *dotdot,
+			  struct rev_info *revs, int symmetric)
+{
+	if (revs->ignore_missing)
+		return 0;
+	/* de-munge so we report the full argument */
+	*dotdot = '.';
+	die(symmetric
+	    ? "Invalid symmetric difference expression %s"
+	    : "Invalid revision range %s", arg);
+}
+
+static int handle_dotdot_1(const char *arg, char *dotdot,
+			   struct rev_info *revs, int flags,
+			   int cant_be_filename,
+			   struct object_context *a_oc,
+			   struct object_context *b_oc)
+{
+	const char *a_name, *b_name;
+	struct object_id a_oid, b_oid;
+	struct object *a_obj, *b_obj;
+	unsigned int a_flags, b_flags;
+	int symmetric = 0;
+	unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
+	unsigned int oc_flags = GET_SHA1_COMMITTISH | GET_SHA1_RECORD_PATH;
+
+	a_name = arg;
+	if (!*a_name)
+		a_name = "HEAD";
+
+	b_name = dotdot + 2;
+	if (*b_name == '.') {
+		symmetric = 1;
+		b_name++;
+	}
+	if (!*b_name)
+		b_name = "HEAD";
+
+	if (get_sha1_with_context(a_name, oc_flags, a_oid.hash, a_oc) ||
+	    get_sha1_with_context(b_name, oc_flags, b_oid.hash, b_oc))
+		return -1;
+
+	if (!cant_be_filename) {
+		*dotdot = '.';
+		verify_non_filename(revs->prefix, arg);
+		*dotdot = '\0';
+	}
+
+	a_obj = parse_object(&a_oid);
+	b_obj = parse_object(&b_oid);
+	if (!a_obj || !b_obj)
+		return dotdot_missing(arg, dotdot, revs, symmetric);
+
+	if (!symmetric) {
+		/* just A..B */
+		b_flags = flags;
+		a_flags = flags_exclude;
+	} else {
+		/* A...B -- find merge bases between the two */
+		struct commit *a, *b;
+		struct commit_list *exclude;
+
+		a = lookup_commit_reference(&a_obj->oid);
+		b = lookup_commit_reference(&b_obj->oid);
+		if (!a || !b)
+			return dotdot_missing(arg, dotdot, revs, symmetric);
+
+		exclude = get_merge_bases(a, b);
+		add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
+				     flags_exclude);
+		add_pending_commit_list(revs, exclude, flags_exclude);
+		free_commit_list(exclude);
+
+		b_flags = flags;
+		a_flags = flags | SYMMETRIC_LEFT;
+	}
+
+	a_obj->flags |= a_flags;
+	b_obj->flags |= b_flags;
+	add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
+	add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
+	add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
+	add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
+	return 0;
+}
+
+static int handle_dotdot(const char *arg,
+			 struct rev_info *revs, int flags,
+			 int cant_be_filename)
+{
+	struct object_context a_oc, b_oc;
+	char *dotdot = strstr(arg, "..");
+	int ret;
+
+	if (!dotdot)
+		return -1;
+
+	memset(&a_oc, 0, sizeof(a_oc));
+	memset(&b_oc, 0, sizeof(b_oc));
+
+	*dotdot = '\0';
+	ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
+			      &a_oc, &b_oc);
+	*dotdot = '.';
+
+	free(a_oc.path);
+	free(b_oc.path);
+
+	return ret;
+}
+
 int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
 {
 	struct object_context oc;
-	char *dotdot;
+	char *mark;
 	struct object *object;
 	struct object_id oid;
 	int local_flags;
 	const char *arg = arg_;
 	int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
-	unsigned get_sha1_flags = 0;
+	unsigned get_sha1_flags = GET_SHA1_RECORD_PATH;
 
 	flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
 
-	dotdot = strstr(arg, "..");
-	if (dotdot) {
-		struct object_id from_oid;
-		const char *next = dotdot + 2;
-		const char *this = arg;
-		int symmetric = *next == '.';
-		unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
-		static const char head_by_default[] = "HEAD";
-		unsigned int a_flags;
-
-		*dotdot = 0;
-		next += symmetric;
-
-		if (!*next)
-			next = head_by_default;
-		if (dotdot == arg)
-			this = head_by_default;
-		if (this == head_by_default && next == head_by_default &&
-		    !symmetric) {
-			/*
-			 * Just ".."?  That is not a range but the
-			 * pathspec for the parent directory.
-			 */
-			if (!cant_be_filename) {
-				*dotdot = '.';
-				return -1;
-			}
-		}
-		if (!get_sha1_committish(this, from_oid.hash) &&
-		    !get_sha1_committish(next, oid.hash)) {
-			struct object *a_obj, *b_obj;
-
-			if (!cant_be_filename) {
-				*dotdot = '.';
-				verify_non_filename(revs->prefix, arg);
-			}
-
-			a_obj = parse_object(&from_oid);
-			b_obj = parse_object(&oid);
-			if (!a_obj || !b_obj) {
-			missing:
-				if (revs->ignore_missing)
-					return 0;
-				die(symmetric
-				    ? "Invalid symmetric difference expression %s"
-				    : "Invalid revision range %s", arg);
-			}
-
-			if (!symmetric) {
-				/* just A..B */
-				a_flags = flags_exclude;
-			} else {
-				/* A...B -- find merge bases between the two */
-				struct commit *a, *b;
-				struct commit_list *exclude;
-
-				a = (a_obj->type == OBJ_COMMIT
-				     ? (struct commit *)a_obj
-				     : lookup_commit_reference(&a_obj->oid));
-				b = (b_obj->type == OBJ_COMMIT
-				     ? (struct commit *)b_obj
-				     : lookup_commit_reference(&b_obj->oid));
-				if (!a || !b)
-					goto missing;
-				exclude = get_merge_bases(a, b);
-				add_rev_cmdline_list(revs, exclude,
-						     REV_CMD_MERGE_BASE,
-						     flags_exclude);
-				add_pending_commit_list(revs, exclude,
-							flags_exclude);
-				free_commit_list(exclude);
-
-				a_flags = flags | SYMMETRIC_LEFT;
-			}
-
-			a_obj->flags |= a_flags;
-			b_obj->flags |= flags;
-			add_rev_cmdline(revs, a_obj, this,
-					REV_CMD_LEFT, a_flags);
-			add_rev_cmdline(revs, b_obj, next,
-					REV_CMD_RIGHT, flags);
-			add_pending_object(revs, a_obj, this);
-			add_pending_object(revs, b_obj, next);
-			return 0;
-		}
-		*dotdot = '.';
+	if (!cant_be_filename && !strcmp(arg, "..")) {
+		/*
+		 * Just ".."?  That is not a range but the
+		 * pathspec for the parent directory.
+		 */
+		return -1;
 	}
 
-	dotdot = strstr(arg, "^@");
-	if (dotdot && !dotdot[2]) {
-		*dotdot = 0;
+	if (!handle_dotdot(arg, revs, flags, revarg_opt))
+		return 0;
+
+	mark = strstr(arg, "^@");
+	if (mark && !mark[2]) {
+		*mark = 0;
 		if (add_parents_only(revs, arg, flags, 0))
 			return 0;
-		*dotdot = '^';
+		*mark = '^';
 	}
-	dotdot = strstr(arg, "^!");
-	if (dotdot && !dotdot[2]) {
-		*dotdot = 0;
+	mark = strstr(arg, "^!");
+	if (mark && !mark[2]) {
+		*mark = 0;
 		if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
-			*dotdot = '^';
+			*mark = '^';
 	}
-	dotdot = strstr(arg, "^-");
-	if (dotdot) {
+	mark = strstr(arg, "^-");
+	if (mark) {
 		int exclude_parent = 1;
 
-		if (dotdot[2]) {
+		if (mark[2]) {
 			char *end;
-			exclude_parent = strtoul(dotdot + 2, &end, 10);
+			exclude_parent = strtoul(mark + 2, &end, 10);
 			if (*end != '\0' || !exclude_parent)
 				return -1;
 		}
 
-		*dotdot = 0;
+		*mark = 0;
 		if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
-			*dotdot = '^';
+			*mark = '^';
 	}
 
 	local_flags = 0;
@@ -1566,7 +1600,7 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 	}
 
 	if (revarg_opt & REVARG_COMMITTISH)
-		get_sha1_flags = GET_SHA1_COMMITTISH;
+		get_sha1_flags |= GET_SHA1_COMMITTISH;
 
 	if (get_sha1_with_context(arg, get_sha1_flags, oid.hash, &oc))
 		return revs->ignore_missing ? 0 : -1;
@@ -1574,7 +1608,8 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 		verify_non_filename(revs->prefix, arg);
 	object = get_reference(revs, arg, &oid, flags ^ local_flags);
 	add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
-	add_pending_object_with_mode(revs, object, arg, oc.mode);
+	add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
+	free(oc.path);
 	return 0;
 }
 
diff --git a/sha1_name.c b/sha1_name.c
index 389276e..e9ffe68 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1511,6 +1511,7 @@ static int get_sha1_with_context_1(const char *name,
 
 	memset(oc, 0, sizeof(*oc));
 	oc->mode = S_IFINVALID;
+	strbuf_init(&oc->symlink_path, 0);
 	ret = get_sha1_1(name, namelen, sha1, flags);
 	if (!ret)
 		return ret;
@@ -1549,7 +1550,8 @@ static int get_sha1_with_context_1(const char *name,
 			namelen = strlen(cp);
 		}
 
-		strlcpy(oc->path, cp, sizeof(oc->path));
+		if (flags & GET_SHA1_RECORD_PATH)
+			oc->path = xstrdup(cp);
 
 		if (!active_cache)
 			read_cache();
@@ -1612,7 +1614,8 @@ static int get_sha1_with_context_1(const char *name,
 				}
 			}
 			hashcpy(oc->tree, tree_sha1);
-			strlcpy(oc->path, filename, sizeof(oc->path));
+			if (flags & GET_SHA1_RECORD_PATH)
+				oc->path = xstrdup(filename);
 
 			free(new_filename);
 			return ret;
@@ -1638,9 +1641,9 @@ void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
 	get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
 }
 
-int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
+int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *oc)
 {
 	if (flags & GET_SHA1_FOLLOW_SYMLINKS && flags & GET_SHA1_ONLY_TO_DIE)
 		die("BUG: incompatible flags for get_sha1_with_context");
-	return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
+	return get_sha1_with_context_1(str, flags, NULL, sha1, oc);
 }
diff --git a/t/t4063-diff-blobs.sh b/t/t4063-diff-blobs.sh
new file mode 100755
index 0000000..bc69e26
--- /dev/null
+++ b/t/t4063-diff-blobs.sh
@@ -0,0 +1,96 @@
+#!/bin/sh
+
+test_description='test direct comparison of blobs via git-diff'
+. ./test-lib.sh
+
+run_diff () {
+	# use full-index to make it easy to match the index line
+	git diff --full-index "$@" >diff
+}
+
+check_index () {
+	grep "^index $1\\.\\.$2" diff
+}
+
+check_mode () {
+	grep "^old mode $1" diff &&
+	grep "^new mode $2" diff
+}
+
+check_paths () {
+	grep "^diff --git a/$1 b/$2" diff
+}
+
+test_expect_success 'create some blobs' '
+	echo one >one &&
+	echo two >two &&
+	chmod +x two &&
+	git add . &&
+
+	# cover systems where modes are ignored
+	git update-index --chmod=+x two &&
+
+	git commit -m base &&
+
+	sha1_one=$(git rev-parse HEAD:one) &&
+	sha1_two=$(git rev-parse HEAD:two)
+'
+
+test_expect_success 'diff by sha1' '
+	run_diff $sha1_one $sha1_two
+'
+test_expect_success 'index of sha1 diff' '
+	check_index $sha1_one $sha1_two
+'
+test_expect_success 'sha1 diff uses arguments as paths' '
+	check_paths $sha1_one $sha1_two
+'
+test_expect_success 'sha1 diff has no mode change' '
+	! grep mode diff
+'
+
+test_expect_success 'diff by tree:path (run)' '
+	run_diff HEAD:one HEAD:two
+'
+test_expect_success 'index of tree:path diff' '
+	check_index $sha1_one $sha1_two
+'
+test_expect_success 'tree:path diff uses filenames as paths' '
+	check_paths one two
+'
+test_expect_success 'tree:path diff shows mode change' '
+	check_mode 100644 100755
+'
+
+test_expect_success 'diff by ranged tree:path' '
+	run_diff HEAD:one..HEAD:two
+'
+test_expect_success 'index of ranged tree:path diff' '
+	check_index $sha1_one $sha1_two
+'
+test_expect_success 'ranged tree:path diff uses filenames as paths' '
+	check_paths one two
+'
+test_expect_success 'ranged tree:path diff shows mode change' '
+	check_mode 100644 100755
+'
+
+test_expect_success 'diff blob against file' '
+	run_diff HEAD:one two
+'
+test_expect_success 'index of blob-file diff' '
+	check_index $sha1_one $sha1_two
+'
+test_expect_success 'blob-file diff uses filename as paths' '
+	check_paths one two
+'
+test_expect_success FILEMODE 'blob-file diff shows mode change' '
+	check_mode 100644 100755
+'
+
+test_expect_success 'blob-file diff prefers filename to sha1' '
+	run_diff $sha1_one two &&
+	check_paths two two
+'
+
+test_done
diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index 6499cdf..e444195 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -1392,4 +1392,13 @@ test_expect_success 'log --source paints tag names' '
 	test_cmp expect actual
 '
 
+test_expect_success 'log --source paints symmetric ranges' '
+	cat >expect <<-\EOF &&
+	09e12a9	source-b three
+	8e393e1	source-a two
+	EOF
+	git log --oneline --source source-a...source-b >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/tree-walk.c b/tree-walk.c
index f25a08f..6a42e40 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -589,7 +589,6 @@ enum follow_symlinks_result get_tree_entry_follow_symlinks(unsigned char *tree_s
 	int i;
 
 	init_tree_desc(&t, NULL, 0UL);
-	strbuf_init(result_path, 0);
 	strbuf_addstr(&namebuf, name);
 	hashcpy(current_tree_sha1, tree_sha1);