Merge branch 'js/color-diff' into next

* js/color-diff:
  Add the --color-words option to the diff options family
  Add Documentation/howto/setup-git-server-over-http.txt

Documentation/diff-options.txt

@@ -36,6 +36,9 @@
 	Turn off colored diff, even when the configuration file
 	gives the default to color output.
 
+--color-words::
+	Show colored word diff, i.e. color words which have changed.
+
 --no-renames::
 	Turn off rename detection, even when the configuration
 	file gives the default to do so.

Documentation/howto/setup-git-server-over-http.txt

@@ -0,0 +1,256 @@
+From: Rutger Nijlunsing <rutger@nospam.com>
+Subject: Setting up a git repository which can be pushed into and pulled from over HTTP.
+Date: Thu, 10 Aug 2006 22:00:26 +0200
+
+Since Apache is one of those packages people like to compile
+themselves while others prefer the bureaucrat's dream Debian, it is
+impossible to give guidelines which will work for everyone. Just send
+some feedback to the mailing list at git@vger.kernel.org to get this
+document tailored to your favorite distro.
+
+
+What's needed:
+
+- Have an Apache web-server
+
+  On Debian:
+    $ apt-get install apache2
+    To get apache2 by default started,
+    edit /etc/default/apache2 and set NO_START=0
+
+- can edit the configuration of it.
+
+  This could be found under /etc/httpd, or refer to your Apache documentation.
+
+  On Debian: this means being able to edit files under /etc/apache2
+
+- can restart it.
+
+  'apachectl --graceful' might do. If it doesn't, just stop and
+  restart apache. Be warning that active connections to your server
+  might be aborted by this.
+
+  On Debian:
+    $ /etc/init.d/apache2 restart
+  or
+    $ /etc/init.d/apache2 force-reload
+    (which seems to do the same)
+  This adds symlinks from the /etc/apache2/mods-enabled to
+  /etc/apache2/mods-available.
+
+- have permissions to chown a directory
+
+- have git installed at the server _and_ client
+
+In effect, this probably means you're going to be root.
+
+
+Step 1: setup a bare GIT repository
+-----------------------------------
+
+At the time of writing, git-http-push cannot remotely create a GIT
+repository. So we have to do that at the server side with git. Another
+option would be to generate an empty repository at the client and copy
+it to the server with WebDAV. But then you're probably the first to
+try that out :)
+
+Create the directory under the DocumentRoot of the directories served
+by Apache. As an example we take /usr/local/apache2, but try "grep
+DocumentRoot /where/ever/httpd.conf" to find your root:
+
+    $ cd /usr/local/apache/htdocs
+    $ mkdir my-new-repo.git
+
+  On Debian:
+
+    $ cd /var/www
+    $ mkdir my-new-repo.git
+
+
+Initialize a bare repository
+
+    $ cd my-new-repo.git
+    $ git --bare init-db
+
+
+Change the ownership to your web-server's credentials. Use "grep ^User
+httpd.conf" and "grep ^Group httpd.conf" to find out:
+
+    $ chown -R www.www .
+
+  On Debian:
+
+    $ chown -R www-data.www-data .
+
+
+If you do not know which user Apache runs as, you can alternatively do
+a "chmod -R a+w .", inspect the files which are created later on, and
+set the permissions appropriately.
+
+Restart apache2, and check whether http://server/my-new-repo.git gives
+a directory listing. If not, check whether apache started up
+successfully.
+
+
+Step 2: enable DAV on this repository
+-------------------------------------
+
+First make sure the dav_module is loaded. For this, insert in httpd.conf:
+
+    LoadModule dav_module libexec/httpd/libdav.so
+    AddModule mod_dav.c
+
+Also make sure that this line exists which is the file used for
+locking DAV operations:
+
+  DAVLockDB "/usr/local/apache2/temp/DAV.lock"
+
+  On Debian these steps can be performed with:
+
+    Enable the dav and dav_fs modules of apache:
+    $ a2enmod dav_fs
+    (just to be sure. dav_fs might be unneeded, I don't know)
+    $ a2enmod dav
+    The DAV lock is located in /etc/apache2/mods-available/dav_fs.conf:
+      DAVLockDB /var/lock/apache2/DAVLock
+
+Of course, it can point somewhere else, but the string is actually just a
+prefix in some Apache configurations, and therefore the _directory_ has to
+be writable by the user Apache runs as.
+
+Then, add something like this to your httpd.conf
+
+  <Location /my-new-repo.git>
+     DAV on
+     AuthType Basic
+     AuthName "Git"
+     AuthUserFile /usr/local/apache2/conf/passwd.git
+     Require valid-user
+  </Location>
+
+  On Debian:
+    Create (or add to) /etc/apache2/conf.d/git.conf :
+
+    <Location /my-new-repo.git>
+       DAV on
+       AuthType Basic
+       AuthName "Git"
+       AuthUserFile /etc/apache2/passwd.git
+       Require valid-user
+    </Location>
+
+    Debian automatically reads all files under /etc/apach2/conf.d.
+
+The password file can be somewhere else, but it has to be readable by
+Apache and preferably not readable by the world.
+
+Create this file by
+    $ htpasswd -c /usr/local/apache2/conf/passwd.git <user>
+
+    On Debian:
+      $ htpasswd -c /etc/apache2/passwd.git <user>
+
+You will be asked a password, and the file is created. Subsequent calls
+to htpasswd should omit the '-c' option, since you want to append to the
+existing file.
+
+You need to restart Apache.
+
+Now go to http://<username>@<servername>/my-new-repo.git in your
+browser to check whether it asks for a password and accepts the right
+password.
+
+On Debian:
+
+   To test the WebDAV part, do:
+
+   $ apt-get install litmus
+   $ litmus http://<servername>/my-new-repo.git <username> <password>
+
+   Most tests should pass.
+
+A command line tool to test WebDAV is cadaver.
+
+If you're into Windows, from XP onwards Internet Explorer supports
+WebDAV. For this, do Internet Explorer -> Open Location ->
+http://<servername>/my-new-repo.git [x] Open as webfolder -> login .
+
+
+Step 3: setup the client
+------------------------
+
+Make sure that you have HTTP support, i.e. your git was built with curl.
+The easiest way to check is to look for the executable 'git-http-push'.
+
+Then, add the following to your $HOME/.netrc (you can do without, but will be
+asked to input your password a _lot_ of times):
+
+    machine <servername>
+    login <username>
+    password <password>
+
+...and set permissions:
+     chmod 600 ~/.netrc
+
+If you want to access the web-server by its IP, you have to type that in,
+instead of the server name.
+
+To check whether all is OK, do:
+
+   curl --netrc --location -v http://<username>@<servername>/my-new-repo.git/
+
+...this should give a directory listing in HTML of /var/www/my-new-repo.git .
+
+
+Now, add the remote in your existing repository which contains the project
+you want to export:
+
+   $ git-repo-config remote.upload.url \
+       http://<username>@<servername>/my-new-repo.git/
+
+It is important to put the last '/'; Without it, the server will send
+a redirect which git-http-push does not (yet) understand, and git-http-push
+will repeat the request infinitely.
+
+
+Step 4: make the initial push
+-----------------------------
+
+From your client repository, do
+
+   $ git push upload master
+
+This pushes branch 'master' (which is assumed to be the branch you
+want to export) to repository called 'upload', which we previously
+defined with git-repo-config.
+
+
+Troubleshooting:
+----------------
+
+If git-http-push says
+
+   Error: no DAV locking support on remote repo http://...
+
+then it means the web-server did not accept your authentication. Make sure
+that the user name and password matches in httpd.conf, .netrc and the URL
+you are uploading to.
+
+If git-http-push shows you an error (22/502) when trying to MOVE a blob,
+it means that your web-server somehow does not recognize its name in the
+request; This can happen when you start Apache, but then disable the
+network interface. A simple restart of Apache helps.
+
+Errors like (22/502) are of format (curl error code/http error
+code). So (22/404) means something like 'not found' at the server.
+
+Reading /usr/local/apache2/logs/error_log is often helpful.
+
+  On Debian: Read /var/log/apache2/error.log instead.
+
+
+Debian References: http://www.debian-administration.org/articles/285
+
+Authors
+  Johannes Schindelin <Johannes.Schindelin@gmx.de>
+  Rutger Nijlunsing <git@wingding.demon.nl>

diff.c

@@ -358,12 +358,152 @@ static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 	return 0;
 }
 
+struct diff_words_buffer {
+	mmfile_t text;
+	long alloc;
+	long current; /* output pointer */
+	int suppressed_newline;
+};
+
+static void diff_words_append(char *line, unsigned long len,
+		struct diff_words_buffer *buffer)
+{
+	if (buffer->text.size + len > buffer->alloc) {
+		buffer->alloc = (buffer->text.size + len) * 3 / 2;
+		buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
+	}
+	line++;
+	len--;
+	memcpy(buffer->text.ptr + buffer->text.size, line, len);
+	buffer->text.size += len;
+}
+
+struct diff_words_data {
+	struct xdiff_emit_state xm;
+	struct diff_words_buffer minus, plus;
+};
+
+static void print_word(struct diff_words_buffer *buffer, int len, int color,
+		int suppress_newline)
+{
+	const char *ptr;
+	int eol = 0;
+
+	if (len == 0)
+		return;
+
+	ptr  = buffer->text.ptr + buffer->current;
+	buffer->current += len;
+
+	if (ptr[len - 1] == '\n') {
+		eol = 1;
+		len--;
+	}
+
+	fputs(diff_get_color(1, color), stdout);
+	fwrite(ptr, len, 1, stdout);
+	fputs(diff_get_color(1, DIFF_RESET), stdout);
+
+	if (eol) {
+		if (suppress_newline)
+			buffer->suppressed_newline = 1;
+		else
+			putchar('\n');
+	}
+}
+
+static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
+{
+	struct diff_words_data *diff_words = priv;
+
+	if (diff_words->minus.suppressed_newline) {
+		if (line[0] != '+')
+			putchar('\n');
+		diff_words->minus.suppressed_newline = 0;
+	}
+
+	len--;
+	switch (line[0]) {
+		case '-':
+			print_word(&diff_words->minus, len, DIFF_FILE_OLD, 1);
+			break;
+		case '+':
+			print_word(&diff_words->plus, len, DIFF_FILE_NEW, 0);
+			break;
+		case ' ':
+			print_word(&diff_words->plus, len, DIFF_PLAIN, 0);
+			diff_words->minus.current += len;
+			break;
+	}
+}
+
+/* this executes the word diff on the accumulated buffers */
+static void diff_words_show(struct diff_words_data *diff_words)
+{
+	xpparam_t xpp;
+	xdemitconf_t xecfg;
+	xdemitcb_t ecb;
+	mmfile_t minus, plus;
+	int i;
+
+	minus.size = diff_words->minus.text.size;
+	minus.ptr = xmalloc(minus.size);
+	memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
+	for (i = 0; i < minus.size; i++)
+		if (isspace(minus.ptr[i]))
+			minus.ptr[i] = '\n';
+	diff_words->minus.current = 0;
+
+	plus.size = diff_words->plus.text.size;
+	plus.ptr = xmalloc(plus.size);
+	memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
+	for (i = 0; i < plus.size; i++)
+		if (isspace(plus.ptr[i]))
+			plus.ptr[i] = '\n';
+	diff_words->plus.current = 0;
+
+	xpp.flags = XDF_NEED_MINIMAL;
+	xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
+	xecfg.flags = 0;
+	ecb.outf = xdiff_outf;
+	ecb.priv = diff_words;
+	diff_words->xm.consume = fn_out_diff_words_aux;
+	xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
+
+	free(minus.ptr);
+	free(plus.ptr);
+	diff_words->minus.text.size = diff_words->plus.text.size = 0;
+
+	if (diff_words->minus.suppressed_newline) {
+		putchar('\n');
+		diff_words->minus.suppressed_newline = 0;
+	}
+}
+
 struct emit_callback {
 	struct xdiff_emit_state xm;
 	int nparents, color_diff;
 	const char **label_path;
+	struct diff_words_data *diff_words;
 };
 
+static void free_diff_words_data(struct emit_callback *ecbdata)
+{
+	if (ecbdata->diff_words) {
+		/* flush buffers */
+		if (ecbdata->diff_words->minus.text.size ||
+				ecbdata->diff_words->plus.text.size)
+			diff_words_show(ecbdata->diff_words);
+
+		if (ecbdata->diff_words->minus.text.ptr)
+			free (ecbdata->diff_words->minus.text.ptr);
+		if (ecbdata->diff_words->plus.text.ptr)
+			free (ecbdata->diff_words->plus.text.ptr);
+		free(ecbdata->diff_words);
+		ecbdata->diff_words = NULL;
+	}
+}
+
 const char *diff_get_color(int diff_use_color, enum color_diff ix)
 {
 	if (diff_use_color)
@@ -398,12 +538,31 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 	else {
 		int nparents = ecbdata->nparents;
 		int color = DIFF_PLAIN;
-		for (i = 0; i < nparents && len; i++) {
-			if (line[i] == '-')
-				color = DIFF_FILE_OLD;
-			else if (line[i] == '+')
-				color = DIFF_FILE_NEW;
-		}
+		if (ecbdata->diff_words && nparents != 1)
+			/* fall back to normal diff */
+			free_diff_words_data(ecbdata);
+		if (ecbdata->diff_words) {
+			if (line[0] == '-') {
+				diff_words_append(line, len,
+						&ecbdata->diff_words->minus);
+				return;
+			} else if (line[0] == '+') {
+				diff_words_append(line, len,
+						&ecbdata->diff_words->plus);
+				return;
+			}
+			if (ecbdata->diff_words->minus.text.size ||
+					ecbdata->diff_words->plus.text.size)
+				diff_words_show(ecbdata->diff_words);
+			line++;
+			len--;
+		} else
+			for (i = 0; i < nparents && len; i++) {
+				if (line[i] == '-')
+					color = DIFF_FILE_OLD;
+				else if (line[i] == '+')
+					color = DIFF_FILE_NEW;
+			}
 		set = diff_get_color(ecbdata->color_diff, color);
 	}
 	if (len > 0 && line[len-1] == '\n')
@@ -836,7 +995,12 @@ static void builtin_diff(const char *name_a,
 		ecb.outf = xdiff_outf;
 		ecb.priv = &ecbdata;
 		ecbdata.xm.consume = fn_out_consume;
+		if (o->color_diff_words)
+			ecbdata.diff_words =
+				xcalloc(1, sizeof(struct diff_words_data));
 		xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+		if (o->color_diff_words)
+			free_diff_words_data(&ecbdata);
 	}
 
  free_ab_and_return:
@@ -1710,6 +1874,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		options->xdl_opts |= XDF_IGNORE_WHITESPACE;
 	else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
 		options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
+	else if (!strcmp(arg, "--color-words"))
+		options->color_diff = options->color_diff_words = 1;
 	else if (!strcmp(arg, "--no-renames"))
 		options->detect_rename = 0;
 	else

diff.h

@@ -46,7 +46,8 @@ struct diff_options {
 		 full_index:1,
 		 silent_on_remove:1,
 		 find_copies_harder:1,
-		 color_diff:1;
+		 color_diff:1,
+		 color_diff_words:1;
 	int context;
 	int break_opt;
 	int detect_rename;