format-patch: Produce better output with --inline or --attach

This patch makes two small changes to improve the output of --inline
and --attach.

The first is to write a newline preceding the boundary. This is needed because
MIME defines the encapsulation boundary as including the preceding CRLF (or in
this case, just LF), so we should be writing one. Without this, the last
newline in the pre-diff content is consumed instead.

The second change is to always write the line termination character
(default: newline) even when using --inline or --attach. This is simply to
improve the aesthetics of the resulting message. When using --inline an email
client should render the resulting message identically to the non-inline
version. And when using --attach this adds a blank line preceding the
attachment in the email, which is visually attractive.

Signed-off-by: Kevin Ballard <kevin@sb.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

10 files changed, 34 insertions, 3 deletions

diff --git a/diff.c b/diff.c
index a07812c..cbf2547 100644
--- a/diff.c
+++ b/diff.c
@@ -3223,11 +3223,10 @@ void diff_flush(struct diff_options *options)
 
 	if (output_format & DIFF_FORMAT_PATCH) {
 		if (separator) {
+			putc(options->line_termination, options->file);
 			if (options->stat_sep) {
 				/* attach patch instead of inline */
 				fputs(options->stat_sep, options->file);
-			} else {
-				putc(options->line_termination, options->file);
 			}
 		}
 
diff --git a/log-tree.c b/log-tree.c
index 5505606..bd8b9e4 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -198,7 +198,7 @@ void log_write_email_headers(struct rev_info *opt, const char *name,
 		extra_headers = subject_buffer;
 
 		snprintf(buffer, sizeof(buffer) - 1,
-			 "--%s%s\n"
+			 "\n--%s%s\n"
 			 "Content-Type: text/x-patch;"
 			 " name=\"%s.diff\"\n"
 			 "Content-Transfer-Encoding: 8bit\n"
diff --git a/t/t4013/diff.format-patch_--attach_--stdout_initial..master b/t/t4013/diff.format-patch_--attach_--stdout_initial..master
index cf6891f..43346b9 100644
--- a/t/t4013/diff.format-patch_--attach_--stdout_initial..master
+++ b/t/t4013/diff.format-patch_--attach_--stdout_initial..master
@@ -19,6 +19,8 @@ This is the second commit.
  file2   |    3 ---
  3 files changed, 5 insertions(+), 3 deletions(-)
  delete mode 100644 file2
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44.diff"
 Content-Transfer-Encoding: 8bit
@@ -75,6 +77,8 @@ Content-Transfer-Encoding: 8bit
  file1   |    3 +++
  2 files changed, 5 insertions(+), 0 deletions(-)
  create mode 100644 file1
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0.diff"
 Content-Transfer-Encoding: 8bit
@@ -122,6 +126,8 @@ Content-Transfer-Encoding: 8bit
  file3   |    4 ++++
  3 files changed, 9 insertions(+), 0 deletions(-)
  create mode 100644 file3
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a.diff"
 Content-Transfer-Encoding: 8bit
diff --git a/t/t4013/diff.format-patch_--attach_--stdout_initial..master^ b/t/t4013/diff.format-patch_--attach_--stdout_initial..master^
index fe02587..d7490a9 100644
--- a/t/t4013/diff.format-patch_--attach_--stdout_initial..master^
+++ b/t/t4013/diff.format-patch_--attach_--stdout_initial..master^
@@ -19,6 +19,8 @@ This is the second commit.
  file2   |    3 ---
  3 files changed, 5 insertions(+), 3 deletions(-)
  delete mode 100644 file2
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44.diff"
 Content-Transfer-Encoding: 8bit
@@ -75,6 +77,8 @@ Content-Transfer-Encoding: 8bit
  file1   |    3 +++
  2 files changed, 5 insertions(+), 0 deletions(-)
  create mode 100644 file1
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0.diff"
 Content-Transfer-Encoding: 8bit
diff --git a/t/t4013/diff.format-patch_--attach_--stdout_initial..side b/t/t4013/diff.format-patch_--attach_--stdout_initial..side
index 9ff828e..38f7902 100644
--- a/t/t4013/diff.format-patch_--attach_--stdout_initial..side
+++ b/t/t4013/diff.format-patch_--attach_--stdout_initial..side
@@ -17,6 +17,8 @@ Content-Transfer-Encoding: 8bit
  file3   |    4 ++++
  3 files changed, 9 insertions(+), 0 deletions(-)
  create mode 100644 file3
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a.diff"
 Content-Transfer-Encoding: 8bit
diff --git a/t/t4013/diff.format-patch_--inline_--stdout_--subject-prefix=TESTCASE_initial..master b/t/t4013/diff.format-patch_--inline_--stdout_--subject-prefix=TESTCASE_initial..master
index a8093be..fca5cce 100644
--- a/t/t4013/diff.format-patch_--inline_--stdout_--subject-prefix=TESTCASE_initial..master
+++ b/t/t4013/diff.format-patch_--inline_--stdout_--subject-prefix=TESTCASE_initial..master
@@ -19,6 +19,8 @@ This is the second commit.
  file2   |    3 ---
  3 files changed, 5 insertions(+), 3 deletions(-)
  delete mode 100644 file2
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44.diff"
 Content-Transfer-Encoding: 8bit
@@ -75,6 +77,8 @@ Content-Transfer-Encoding: 8bit
  file1   |    3 +++
  2 files changed, 5 insertions(+), 0 deletions(-)
  create mode 100644 file1
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0.diff"
 Content-Transfer-Encoding: 8bit
@@ -122,6 +126,8 @@ Content-Transfer-Encoding: 8bit
  file3   |    4 ++++
  3 files changed, 9 insertions(+), 0 deletions(-)
  create mode 100644 file3
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a.diff"
 Content-Transfer-Encoding: 8bit
diff --git a/t/t4013/diff.format-patch_--inline_--stdout_initial..master b/t/t4013/diff.format-patch_--inline_--stdout_initial..master
index aa110c0..6d6fac3 100644
--- a/t/t4013/diff.format-patch_--inline_--stdout_initial..master
+++ b/t/t4013/diff.format-patch_--inline_--stdout_initial..master
@@ -19,6 +19,8 @@ This is the second commit.
  file2   |    3 ---
  3 files changed, 5 insertions(+), 3 deletions(-)
  delete mode 100644 file2
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44.diff"
 Content-Transfer-Encoding: 8bit
@@ -75,6 +77,8 @@ Content-Transfer-Encoding: 8bit
  file1   |    3 +++
  2 files changed, 5 insertions(+), 0 deletions(-)
  create mode 100644 file1
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0.diff"
 Content-Transfer-Encoding: 8bit
@@ -122,6 +126,8 @@ Content-Transfer-Encoding: 8bit
  file3   |    4 ++++
  3 files changed, 9 insertions(+), 0 deletions(-)
  create mode 100644 file3
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a.diff"
 Content-Transfer-Encoding: 8bit
diff --git a/t/t4013/diff.format-patch_--inline_--stdout_initial..master^ b/t/t4013/diff.format-patch_--inline_--stdout_initial..master^
index 95e9ea4..18a1110 100644
--- a/t/t4013/diff.format-patch_--inline_--stdout_initial..master^
+++ b/t/t4013/diff.format-patch_--inline_--stdout_initial..master^
@@ -19,6 +19,8 @@ This is the second commit.
  file2   |    3 ---
  3 files changed, 5 insertions(+), 3 deletions(-)
  delete mode 100644 file2
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44.diff"
 Content-Transfer-Encoding: 8bit
@@ -75,6 +77,8 @@ Content-Transfer-Encoding: 8bit
  file1   |    3 +++
  2 files changed, 5 insertions(+), 0 deletions(-)
  create mode 100644 file1
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0.diff"
 Content-Transfer-Encoding: 8bit
diff --git a/t/t4013/diff.format-patch_--inline_--stdout_initial..master^^ b/t/t4013/diff.format-patch_--inline_--stdout_initial..master^^
index b8e81e1..4f258b8 100644
--- a/t/t4013/diff.format-patch_--inline_--stdout_initial..master^^
+++ b/t/t4013/diff.format-patch_--inline_--stdout_initial..master^^
@@ -19,6 +19,8 @@ This is the second commit.
  file2   |    3 ---
  3 files changed, 5 insertions(+), 3 deletions(-)
  delete mode 100644 file2
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44.diff"
 Content-Transfer-Encoding: 8bit
diff --git a/t/t4013/diff.format-patch_--inline_--stdout_initial..side b/t/t4013/diff.format-patch_--inline_--stdout_initial..side
index 86ae923..e86dce6 100644
--- a/t/t4013/diff.format-patch_--inline_--stdout_initial..side
+++ b/t/t4013/diff.format-patch_--inline_--stdout_initial..side
@@ -17,6 +17,8 @@ Content-Transfer-Encoding: 8bit
  file3   |    4 ++++
  3 files changed, 9 insertions(+), 0 deletions(-)
  create mode 100644 file3
+
+
 --------------g-i-t--v-e-r-s-i-o-n
 Content-Type: text/x-patch; name="c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a.diff"
 Content-Transfer-Encoding: 8bit