[PATCH] show: add --follow-symlinks option for :

2018-04-16 Thread Michael Vogt 
Add a --follow-symlinks option that'll resolve symlinks to their
targets when the target is of the form :.

Without it, git will show the path of the link itself if the symlink
is the leaf node of , or otherwise an error if some component
of  is a symlink to another location in the repository. With
the new --follow-symlinks option both will be resolved to their
target, and its content shown instead.

Signed-off-by: Michael Vogt <m...@ubuntu.com>
---
 Documentation/git-show.txt |  7 +++
 builtin/log.c  |  6 +-
 revision.c |  2 ++
 revision.h |  1 +
 t/t1800-git-show.sh| 41 ++
 5 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100755 t/t1800-git-show.sh

diff --git a/Documentation/git-show.txt b/Documentation/git-show.txt
index e73ef5401..e2634b27e 100644
--- a/Documentation/git-show.txt
+++ b/Documentation/git-show.txt
@@ -39,6 +39,13 @@ OPTIONS
For a more complete list of ways to spell object names, see
"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 
+--follow-symlinks::
+   Follow symlinks inside the repository when requesting objects
+   in extended revision syntax of the form tree-ish:path-in-tree.
+   It will resolve any symlinks in  and shows the
+   content of the link if the symlink is the leaf node of
+   .
+
 include::pretty-options.txt[]
 
 
diff --git a/builtin/log.c b/builtin/log.c
index 94ee177d5..7d815b8ea 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -142,7 +142,7 @@ static void cmd_log_init_finish(int argc, const char 
**argv, const char *prefix,
 struct rev_info *rev, struct setup_revision_opt *opt)
 {
struct userformat_want w;
-   int quiet = 0, source = 0, mailmap = 0;
+   int quiet = 0, source = 0, mailmap = 0, follow_symlinks = 0;
static struct line_opt_callback_data line_cb = {NULL, NULL, 
STRING_LIST_INIT_DUP};
static struct string_list decorate_refs_exclude = 
STRING_LIST_INIT_NODUP;
static struct string_list decorate_refs_include = 
STRING_LIST_INIT_NODUP;
@@ -162,6 +162,8 @@ static void cmd_log_init_finish(int argc, const char 
**argv, const char *prefix,
OPT_CALLBACK('L', NULL, _cb, "n,m:file",
 N_("Process line range n,m in file, counting from 
1"),
 log_line_range_callback),
+   OPT_BOOL(0, "follow-symlinks", _symlinks,
+N_("follow in-tree symlinks (used when showing file 
content)")),
OPT_END()
};
 
@@ -176,6 +178,8 @@ static void cmd_log_init_finish(int argc, const char 
**argv, const char *prefix,
 
if (quiet)
rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
+   if (follow_symlinks)
+   rev->follow_symlinks = 1;
argc = setup_revisions(argc, argv, rev, opt);
 
/* Any arguments at this point are not recognized */
diff --git a/revision.c b/revision.c
index b42c836d7..4ab22313f 100644
--- a/revision.c
+++ b/revision.c
@@ -1678,6 +1678,8 @@ int handle_revision_arg(const char *arg_, struct rev_info 
*revs, int flags, unsi
 
if (revarg_opt & REVARG_COMMITTISH)
get_sha1_flags |= GET_OID_COMMITTISH;
+   if (revs && revs->follow_symlinks)
+   get_sha1_flags |= GET_OID_FOLLOW_SYMLINKS;
 
if (get_oid_with_context(arg, get_sha1_flags, , ))
return revs->ignore_missing ? 0 : -1;
diff --git a/revision.h b/revision.h
index b8c47b98e..060f1038a 100644
--- a/revision.h
+++ b/revision.h
@@ -122,6 +122,7 @@ struct rev_info {
first_parent_only:1,
line_level_traverse:1,
tree_blobs_in_commit_order:1,
+   follow_symlinks:1,
 
/* for internal use only */
exclude_promisor_objects:1;
diff --git a/t/t1800-git-show.sh b/t/t1800-git-show.sh
new file mode 100755
index 0..7a02438ec
--- /dev/null
+++ b/t/t1800-git-show.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+test_description='Test git show works'
+
+. ./test-lib.sh
+
+test_expect_success 'verify git show HEAD:foo works' '
+   test_commit A &&
+   git show HEAD:A.t >actual &&
+   echo A >expected &&
+   test_cmp expected actual
+'
+
+test_expect_success SYMLINKS 'verify git show HEAD:symlink shows symlink 
points to foo' '
+   ln -s A.t A.link &&
+   git add A.link &&
+   git commit -m"Added symlink to A.t" &&
+   git show HEAD:A.link >actual &&
+   printf "%s" A.t >expected &&
+   test_cmp expected actual
+'
+
+test_expect_success SYMLINKS 'verify git show --follow-symlinks HEAD:symlink 
shows foo' '
+   git show --follow-symlin

[PATCH v2] show: add --follow-symlinks option for :

2018-04-16 Thread Michael Vogt 
Updated version of the `git show --follow-symlink` patch. This version
includes the feedback from Ævar Arnfjörð Bjarmason and Stefan Beller:

- commit message updated
- test fixes merged from Ævar (thanks!)
- Documentation/git-show.txt clarified

It does not include a test for --follow-symlinks in the dirlink case
when a file is behind a dirlink symlink. This this currently fails with
a non-descriptive error message. I hope to find time to improve this
error message at some point and then a test for this will be added.

It also does not include a test for a repo with symlinks when running
on a system without SYMLINKS. I don't have access to such a system,
sorry.

Re: [RFC PATCH] Add "git show --follow-symlinks HEAD:symlink"

2018-04-13 Thread Michael Vogt 
On Fri, Apr 13, 2018 at 09:33:00PM +0200, Ævar Arnfjörð Bjarmason wrote:
> 
> On Fri, Apr 13 2018, Michael Vogt wrote:
> 
> > The update patch is attached as an inline attachement.
> 
> Your patch still just shows up as a straight-up attachment in many
> E-Mail clients. Note the difference between what your patch
[..]
> This is why Documentation/SubmittingPatches suggests using format-patch
> & send-email. You don't *have* to use those tools, and can use something
> that's compatible with what's expected on-list, but what you're doing
> isn't that.

My apologizes, I resend it using "git send-email".

Cheers,
 Michael

[PATCH] support: git show --follow-symlinks HEAD:symlink

2018-04-13 Thread Michael Vogt 
Add support for the `--follow-symlinks` options to git-show. This
allows to write:

git show --follow-symlink HEAD:path-a-symlink

to get the content of the symlinked file.

Signed-off-by: Michael Vogt <m...@ubuntu.com>
---
 Documentation/git-show.txt |  6 +
 builtin/log.c  |  7 --
 revision.c |  2 ++
 revision.h |  1 +
 t/t1800-git-show.sh| 46 ++
 5 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100755 t/t1800-git-show.sh

diff --git a/Documentation/git-show.txt b/Documentation/git-show.txt
index e73ef5401..d9f7fd90c 100644
--- a/Documentation/git-show.txt
+++ b/Documentation/git-show.txt
@@ -39,6 +39,12 @@ OPTIONS
For a more complete list of ways to spell object names, see
"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 
+--follow-symlinks::
+   Follow symlinks inside the repository when requesting objects
+   in extended revision syntax of the form tree-ish:path-in-tree.
+   Instead of output about the link itself, provide output about
+   the linked-to object.
+
 include::pretty-options.txt[]
 
 
diff --git a/builtin/log.c b/builtin/log.c
index 94ee177d5..e92af4fc7 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -142,7 +142,7 @@ static void cmd_log_init_finish(int argc, const char 
**argv, const char *prefix,
 struct rev_info *rev, struct setup_revision_opt *opt)
 {
struct userformat_want w;
-   int quiet = 0, source = 0, mailmap = 0;
+   int quiet = 0, source = 0, mailmap = 0, follow_symlinks = 0;
static struct line_opt_callback_data line_cb = {NULL, NULL, 
STRING_LIST_INIT_DUP};
static struct string_list decorate_refs_exclude = 
STRING_LIST_INIT_NODUP;
static struct string_list decorate_refs_include = 
STRING_LIST_INIT_NODUP;
@@ -162,6 +162,8 @@ static void cmd_log_init_finish(int argc, const char 
**argv, const char *prefix,
OPT_CALLBACK('L', NULL, _cb, "n,m:file",
 N_("Process line range n,m in file, counting from 
1"),
 log_line_range_callback),
+   OPT_BOOL(0, "follow-symlinks", _symlinks,
+N_("follow in-tree symlinks (used when showing file 
content)")),
OPT_END()
};
 
@@ -173,9 +175,10 @@ static void cmd_log_init_finish(int argc, const char 
**argv, const char *prefix,
 builtin_log_options, builtin_log_usage,
 PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 PARSE_OPT_KEEP_DASHDASH);
-
if (quiet)
rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
+   if (follow_symlinks)
+   rev->follow_symlinks = 1;
argc = setup_revisions(argc, argv, rev, opt);
 
/* Any arguments at this point are not recognized */
diff --git a/revision.c b/revision.c
index b42c836d7..4ab22313f 100644
--- a/revision.c
+++ b/revision.c
@@ -1678,6 +1678,8 @@ int handle_revision_arg(const char *arg_, struct rev_info 
*revs, int flags, unsi
 
if (revarg_opt & REVARG_COMMITTISH)
get_sha1_flags |= GET_OID_COMMITTISH;
+   if (revs && revs->follow_symlinks)
+   get_sha1_flags |= GET_OID_FOLLOW_SYMLINKS;
 
if (get_oid_with_context(arg, get_sha1_flags, , ))
return revs->ignore_missing ? 0 : -1;
diff --git a/revision.h b/revision.h
index b8c47b98e..060f1038a 100644
--- a/revision.h
+++ b/revision.h
@@ -122,6 +122,7 @@ struct rev_info {
first_parent_only:1,
line_level_traverse:1,
tree_blobs_in_commit_order:1,
+   follow_symlinks:1,
 
/* for internal use only */
exclude_promisor_objects:1;
diff --git a/t/t1800-git-show.sh b/t/t1800-git-show.sh
new file mode 100755
index 0..85541b4db
--- /dev/null
+++ b/t/t1800-git-show.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+
+test_description='Test git show works'
+
+. ./test-lib.sh
+
+test_expect_success 'verify git show HEAD:foo works' '
+printf "foo content\n" >foo &&
+git add foo &&
+git commit -m "added foo" &&
+git show HEAD:foo >actual &&
+printf "foo content\n" >expected &&
+test_cmp expected actual
+'
+
+test_expect_success 'verify git show HEAD:symlink shows symlink points to foo' 
'
+printf "foo content\n" >foo &&
+ln -s foo symlink &&
+git add foo symlink &&
+git commit -m "added foo and a symlink to foo" &&
+git show HEAD:foo >actual &&
+printf "foo content\n" >expected &&
+test_cmp expected actual &&

Re: [RFC PATCH] Add "git show --follow-symlinks HEAD:symlink"

2018-04-13 Thread Michael Vogt 
On Fri, Apr 13, 2018 at 10:28:13AM -0700, Stefan Beller wrote:
> Hi Michael,
Hi Stefan,

> thanks for the patch,
Thanks for the review.

[..]
> The patch seems reasonable, apart from minor nits:
> In the test we'd prefer no whitespace on the right side of the redirection,
> i.e. echo content >foo

Sure, updated.

> Instead of evaluating git commands in shell and assigning it to a variable,
> we'd prefer to dump it to files:
[..]

Makes sense, updated.

> There is a typo &.

Ups, sorry! Fixed.

> Can we reword the documentation, such that we do not have
> an occurrence of "extended SHA-1" ?
[..]
> Maybe
> 
> Follow symlinks inside the repository when requesting
> objects in extended revision syntax of the form tree-ish:path-in-tree.

This looks very reasonable, I updated the documentation accordingly.

The update patch is attached as an inline attachement.

Cheers,
 Michael
>From dab10f5e5aea8a31cbee0ab1d5a78204c8c9832a Mon Sep 17 00:00:00 2001
From: Michael Vogt <m...@ubuntu.com>
Date: Mon, 9 Apr 2018 10:38:13 +0200
Subject: [PATCH] support: git show --follow-symlinks HEAD:symlink

Add support for the `--follow-symlinks` options to git-show. This
allows to write:

git show --follow-symlink HEAD:path-a-symlink

to get the content of the symlinked file.

Signed-off-by: Michael Vogt <m...@ubuntu.com>
---
 Documentation/git-show.txt |  6 +
 builtin/log.c  |  7 --
 revision.c |  2 ++
 revision.h |  1 +
 t/t1800-git-show.sh| 46 ++
 5 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100755 t/t1800-git-show.sh

diff --git a/Documentation/git-show.txt b/Documentation/git-show.txt
index e73ef5401..d9f7fd90c 100644
--- a/Documentation/git-show.txt
+++ b/Documentation/git-show.txt
@@ -39,6 +39,12 @@ OPTIONS
 	For a more complete list of ways to spell object names, see
 	"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 
+--follow-symlinks::
+	Follow symlinks inside the repository when requesting objects
+	in extended revision syntax of the form tree-ish:path-in-tree.
+	Instead of output about the link itself, provide output about
+	the linked-to object.
+
 include::pretty-options.txt[]
 
 
diff --git a/builtin/log.c b/builtin/log.c
index 94ee177d5..e92af4fc7 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -142,7 +142,7 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 			 struct rev_info *rev, struct setup_revision_opt *opt)
 {
 	struct userformat_want w;
-	int quiet = 0, source = 0, mailmap = 0;
+	int quiet = 0, source = 0, mailmap = 0, follow_symlinks = 0;
 	static struct line_opt_callback_data line_cb = {NULL, NULL, STRING_LIST_INIT_DUP};
 	static struct string_list decorate_refs_exclude = STRING_LIST_INIT_NODUP;
 	static struct string_list decorate_refs_include = STRING_LIST_INIT_NODUP;
@@ -162,6 +162,8 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 		OPT_CALLBACK('L', NULL, _cb, "n,m:file",
 			 N_("Process line range n,m in file, counting from 1"),
 			 log_line_range_callback),
+		OPT_BOOL(0, "follow-symlinks", _symlinks,
+			 N_("follow in-tree symlinks (used when showing file content)")),
 		OPT_END()
 	};
 
@@ -173,9 +175,10 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 			 builtin_log_options, builtin_log_usage,
 			 PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 			 PARSE_OPT_KEEP_DASHDASH);
-
 	if (quiet)
 		rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
+	if (follow_symlinks)
+		rev->follow_symlinks = 1;
 	argc = setup_revisions(argc, argv, rev, opt);
 
 	/* Any arguments at this point are not recognized */
diff --git a/revision.c b/revision.c
index b42c836d7..4ab22313f 100644
--- a/revision.c
+++ b/revision.c
@@ -1678,6 +1678,8 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 
 	if (revarg_opt & REVARG_COMMITTISH)
 		get_sha1_flags |= GET_OID_COMMITTISH;
+	if (revs && revs->follow_symlinks)
+		get_sha1_flags |= GET_OID_FOLLOW_SYMLINKS;
 
 	if (get_oid_with_context(arg, get_sha1_flags, , ))
 		return revs->ignore_missing ? 0 : -1;
diff --git a/revision.h b/revision.h
index b8c47b98e..060f1038a 100644
--- a/revision.h
+++ b/revision.h
@@ -122,6 +122,7 @@ struct rev_info {
 			first_parent_only:1,
 			line_level_traverse:1,
 			tree_blobs_in_commit_order:1,
+			follow_symlinks:1,
 
 			/* for internal use only */
 			exclude_promisor_objects:1;
diff --git a/t/t1800-git-show.sh b/t/t1800-git-show.sh
new file mode 100755
index 0..85541b4db
--- /dev/null
+++ b/t/t1800-git-show.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+
+test_description='Test git show works'
+
+. ./test-lib.sh
+
+test_expect_success 'verify git show HEAD:foo works' '
+printf "foo content\

Re: [RFC PATCH] Add "git show --follow-symlinks HEAD:symlink"

2018-04-13 Thread Michael Vogt 
Hi Ævar,

thanks for your quick reply!

On Mon, Apr 09, 2018 at 11:28:45AM +0200, Ævar Arnfjörð Bjarmason wrote:
> On Mon, Apr 09 2018, Michael Vogt wrote:
[..]
> > Subject: [PATCH] support: git show --follow-symlinks HEAD:symlink
> >
> > Add support for the `--follow-symlinks` options to git-show. This
> > allows to write:
> >
> > git show --follow-symlink HEAD:path-a-symlink
> 
> The patch looks reasonable, but please submit it as described in
> Documentation/SubmittingPatches, i.e. inline instead of as an
> attachment, and with a signed-off-by line etc. We'd also need some tests
> for this.

Thanks for the intial reivew. I updated the patch with a test and
documentation for the new option. Happy to merge the test into one of
the existing test files, I read t/README and greping around I did not
find a place that looked like a good fit. 

I added the updated patch as an mutt inline attachment now.

Cheers,
 Michael
>From 5a9faa9eff00f316fc654c8e3bc85c3ba56ea659 Mon Sep 17 00:00:00 2001
From: Michael Vogt <m...@ubuntu.com>
Date: Mon, 9 Apr 2018 10:38:13 +0200
Subject: [PATCH] support: git show --follow-symlinks HEAD:symlink

Add support for the `--follow-symlinks` options to git-show. This
allows to write:

git show --follow-symlink HEAD:path-a-symlink

to get the content of the symlinked file.

Signed-off-by: Michael Vogt <m...@ubuntu.com>
---
 Documentation/git-show.txt |  6 ++
 builtin/log.c  |  7 +--
 revision.c |  2 ++
 revision.h |  1 +
 t/t1800-git-show.sh| 41 ++
 5 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100755 t/t1800-git-show.sh

diff --git a/Documentation/git-show.txt b/Documentation/git-show.txt
index e73ef5401..fa751c35d 100644
--- a/Documentation/git-show.txt
+++ b/Documentation/git-show.txt
@@ -39,6 +39,12 @@ OPTIONS
 	For a more complete list of ways to spell object names, see
 	"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 
+--follow-symlinks::
+	Follow symlinks inside the repository when requesting objects
+	with extended SHA-1 expressions of the form tree-ish:path-in-tree.
+	Instead of output about the link itself, provide output about
+	the linked-to object.
+
 include::pretty-options.txt[]
 
 
diff --git a/builtin/log.c b/builtin/log.c
index 94ee177d5..e92af4fc7 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -142,7 +142,7 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 			 struct rev_info *rev, struct setup_revision_opt *opt)
 {
 	struct userformat_want w;
-	int quiet = 0, source = 0, mailmap = 0;
+	int quiet = 0, source = 0, mailmap = 0, follow_symlinks = 0;
 	static struct line_opt_callback_data line_cb = {NULL, NULL, STRING_LIST_INIT_DUP};
 	static struct string_list decorate_refs_exclude = STRING_LIST_INIT_NODUP;
 	static struct string_list decorate_refs_include = STRING_LIST_INIT_NODUP;
@@ -162,6 +162,8 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 		OPT_CALLBACK('L', NULL, _cb, "n,m:file",
 			 N_("Process line range n,m in file, counting from 1"),
 			 log_line_range_callback),
+		OPT_BOOL(0, "follow-symlinks", _symlinks,
+			 N_("follow in-tree symlinks (used when showing file content)")),
 		OPT_END()
 	};
 
@@ -173,9 +175,10 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 			 builtin_log_options, builtin_log_usage,
 			 PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 			 PARSE_OPT_KEEP_DASHDASH);
-
 	if (quiet)
 		rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
+	if (follow_symlinks)
+		rev->follow_symlinks = 1;
 	argc = setup_revisions(argc, argv, rev, opt);
 
 	/* Any arguments at this point are not recognized */
diff --git a/revision.c b/revision.c
index b42c836d7..4ab22313f 100644
--- a/revision.c
+++ b/revision.c
@@ -1678,6 +1678,8 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 
 	if (revarg_opt & REVARG_COMMITTISH)
 		get_sha1_flags |= GET_OID_COMMITTISH;
+	if (revs && revs->follow_symlinks)
+		get_sha1_flags |= GET_OID_FOLLOW_SYMLINKS;
 
 	if (get_oid_with_context(arg, get_sha1_flags, , ))
 		return revs->ignore_missing ? 0 : -1;
diff --git a/revision.h b/revision.h
index b8c47b98e..060f1038a 100644
--- a/revision.h
+++ b/revision.h
@@ -122,6 +122,7 @@ struct rev_info {
 			first_parent_only:1,
 			line_level_traverse:1,
 			tree_blobs_in_commit_order:1,
+			follow_symlinks:1,
 
 			/* for internal use only */
 			exclude_promisor_objects:1;
diff --git a/t/t1800-git-show.sh b/t/t1800-git-show.sh
new file mode 100755
index 0..86fe8ee02
--- /dev/null
+++ b/t/t1800-git-show.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+test_description='Test git show works'
+
+. ./test-lib.sh
+
+test_expect_success 'verify git

[RFC PATCH] Add "git show --follow-symlinks HEAD:symlink"

2018-04-09 Thread Michael Vogt 
Hi,

I noticed that `git show HEAD:path-to-symlink` does not work and
returns an error like:
"fatal: Path 'debian/changelog' exists on disk, but not in 'HEAD'."

Looking at `git show` it seems there is no way right now to make
git-show show blobs if they are symlinks [1].

It would be nice to have this ability. Attached is a draft patch to
allow to write: `git show --follow-symlinks HEAD:path-to-symlink`.
Tests are missing in the patch, I'm happy to add those if there is a
chance for the feature to get in.

Cheers,
 Michael

[1] Using `git cat-file --follow-symlinks --batch < input` works but
feels a bit less elegant compared to supporting it directly in
git-show.
>From 616b7f21c057656960cb6b8a266095bbef734122 Mon Sep 17 00:00:00 2001
From: Michael Vogt <m...@ubuntu.com>
Date: Mon, 9 Apr 2018 10:38:13 +0200
Subject: [PATCH] support: git show --follow-symlinks HEAD:symlink

Add support for the `--follow-symlinks` options to git-show. This
allows to write:

git show --follow-symlink HEAD:path-a-symlink

to get the content of the symlinked file.
---
 builtin/log.c | 7 +--
 revision.c| 2 ++
 revision.h| 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/builtin/log.c b/builtin/log.c
index 94ee177d5..e92af4fc7 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -142,7 +142,7 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 			 struct rev_info *rev, struct setup_revision_opt *opt)
 {
 	struct userformat_want w;
-	int quiet = 0, source = 0, mailmap = 0;
+	int quiet = 0, source = 0, mailmap = 0, follow_symlinks = 0;
 	static struct line_opt_callback_data line_cb = {NULL, NULL, STRING_LIST_INIT_DUP};
 	static struct string_list decorate_refs_exclude = STRING_LIST_INIT_NODUP;
 	static struct string_list decorate_refs_include = STRING_LIST_INIT_NODUP;
@@ -162,6 +162,8 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 		OPT_CALLBACK('L', NULL, _cb, "n,m:file",
 			 N_("Process line range n,m in file, counting from 1"),
 			 log_line_range_callback),
+		OPT_BOOL(0, "follow-symlinks", _symlinks,
+			 N_("follow in-tree symlinks (used when showing file content)")),
 		OPT_END()
 	};
 
@@ -173,9 +175,10 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 			 builtin_log_options, builtin_log_usage,
 			 PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 			 PARSE_OPT_KEEP_DASHDASH);
-
 	if (quiet)
 		rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
+	if (follow_symlinks)
+		rev->follow_symlinks = 1;
 	argc = setup_revisions(argc, argv, rev, opt);
 
 	/* Any arguments at this point are not recognized */
diff --git a/revision.c b/revision.c
index b42c836d7..4ab22313f 100644
--- a/revision.c
+++ b/revision.c
@@ -1678,6 +1678,8 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 
 	if (revarg_opt & REVARG_COMMITTISH)
 		get_sha1_flags |= GET_OID_COMMITTISH;
+	if (revs && revs->follow_symlinks)
+		get_sha1_flags |= GET_OID_FOLLOW_SYMLINKS;
 
 	if (get_oid_with_context(arg, get_sha1_flags, , ))
 		return revs->ignore_missing ? 0 : -1;
diff --git a/revision.h b/revision.h
index b8c47b98e..060f1038a 100644
--- a/revision.h
+++ b/revision.h
@@ -122,6 +122,7 @@ struct rev_info {
 			first_parent_only:1,
 			line_level_traverse:1,
 			tree_blobs_in_commit_order:1,
+			follow_symlinks:1,
 
 			/* for internal use only */
 			exclude_promisor_objects:1;
-- 
2.14.1