Merge branch 'jc/combined'

* jc/combined:
  combine-diff: a few more finishing touches.
  Documentation: clarify refname disambiguation rules.
  diff-format.txt: Combined diff format documentation supplement
  Remove --syslog in git-daemon inetd documentation examples.
  Documentation: updates to "Everyday GIT"

5 files changed, 148 insertions, 54 deletions

diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt
index 617d8f526..ed4ebcbab 100644
--- a/Documentation/diff-format.txt
+++ b/Documentation/diff-format.txt
@@ -156,31 +156,91 @@ to produce 'combined diff', which looks like this:
 
 ------------
 diff --combined describe.c
-@@@ +98,7 @@@
-   return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
+index fabadb8,cc95eb0..4866510
+--- a/describe.c
++++ b/describe.c
+@@@ -98,20 -98,12 +98,20 @@@
+  	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
   }
-
+  
 - static void describe(char *arg)
  -static void describe(struct commit *cmit, int last_one)
 ++static void describe(char *arg, int last_one)
   {
- +     unsigned char sha1[20];
- +     struct commit *cmit;
+ +	unsigned char sha1[20];
+ +	struct commit *cmit;
+  	struct commit_list *list;
+  	static int initialized = 0;
+  	struct commit_name *n;
+  
+ +	if (get_sha1(arg, sha1) < 0)
+ +		usage(describe_usage);
+ +	cmit = lookup_commit_reference(sha1);
+ +	if (!cmit)
+ +		usage(describe_usage);
+ +
+  	if (!initialized) {
+  		initialized = 1;
+  		for_each_ref(get_name);
 ------------
 
+1.   It is preceded with a "git diff" header, that looks like
+     this (when '-c' option is used):
+
+       diff --combined file
++
+or like this (when '--cc' option is used):
+
+       diff --c file
+
+2.   It is followed by one or more extended header lines
+     (this example shows a merge with two parents):
+
+       index <hash>,<hash>..<hash>
+       mode <mode>,<mode>..<mode>
+       new file mode <mode>
+       deleted file mode <mode>,<mode>
++
+The `mode <mode>,<mode>..<mode>` line appears only if at least one of
+the <mode> is diferent from the rest. Extended headers with
+information about detected contents movement (renames and
+copying detection) are designed to work with diff of two
+<tree-ish> and are not used by combined diff format.
+
+3.   It is followed by two-line from-file/to-file header
+
+       --- a/file
+       +++ b/file
++
+Similar to two-line header for traditional 'unified' diff
+format, `/dev/null` is used to signal created or deleted
+files.
+
+4.   Chunk header format is modified to prevent people from
+     accidentally feeding it to `patch -p1`. Combined diff format
+     was created for review of merge commit changes, and was not
+     meant for apply. The change is similar to the change in the
+     extended 'index' header:
+
+       @@@ <from-file-range> <from-file-range> <to-file-range> @@@
++
+There are (number of parents + 1) `@` characters in the chunk
+header for combined diff format.
+
 Unlike the traditional 'unified' diff format, which shows two
 files A and B with a single column that has `-` (minus --
 appears in A but removed in B), `+` (plus -- missing in A but
-added to B), or ` ` (space -- unchanged) prefix, this format
+added to B), or `" "` (space -- unchanged) prefix, this format
 compares two or more files file1, file2,... with one file X, and
 shows how X differs from each of fileN.  One column for each of
 fileN is prepended to the output line to note how X's line is
 different from it.
 
 A `-` character in the column N means that the line appears in
-fileN but it does not appear in the last file.  A `+` character
+fileN but it does not appear in the result.  A `+` character
 in the column N means that the line appears in the last file,
-and fileN does not have that line.
+and fileN does not have that line (in other words, the line was
+added, from the point of view of that parent).
 
 In the above example output, the function signature was changed
 from both files (hence two `-` removals from both file1 and
diff --git a/Documentation/everyday.txt b/Documentation/everyday.txt
index b935c1808..278161f58 100644
--- a/Documentation/everyday.txt
+++ b/Documentation/everyday.txt
@@ -1,22 +1,7 @@
 Everyday GIT With 20 Commands Or So
 ===================================
 
-GIT suite has over 100 commands, and the manual page for each of
-them discusses what the command does and how it is used in
-detail, but until you know what command should be used in order
-to achieve what you want to do, you cannot tell which manual
-page to look at, and if you know that already you do not need
-the manual.
-
-Does that mean you need to know all of them before you can use
-git?  Not at all.  Depending on the role you play, the set of
-commands you need to know is slightly different, but in any case
-what you need to learn is far smaller than the full set of
-commands to carry out your day-to-day work.  This document is to
-serve as a cheat-sheet and a set of pointers for people playing
-various roles.
-
-<<Basic Repository>> commands are needed by people who has a
+<<Basic Repository>> commands are needed by people who have a
 repository --- that is everybody, because every working tree of
 git is a repository.
 
@@ -25,28 +10,27 @@ essential for anybody who makes a commit, even for somebody who
 works alone.
 
 If you work with other people, you will need commands listed in
-<<Individual Developer (Participant)>> section as well.
+the <<Individual Developer (Participant)>> section as well.
 
-People who play <<Integrator>> role need to learn some more
+People who play the <<Integrator>> role need to learn some more
 commands in addition to the above.
 
 <<Repository Administration>> commands are for system
-administrators who are responsible to care and feed git
-repositories to support developers.
+administrators who are responsible for the care and feeding
+of git repositories.
 
 
 Basic Repository[[Basic Repository]]
 ------------------------------------
 
-Everybody uses these commands to feed and care git repositories.
+Everybody uses these commands to maintain git repositories.
 
   * gitlink:git-init-db[1] or gitlink:git-clone[1] to create a
     new repository.
 
-  * gitlink:git-fsck-objects[1] to validate the repository.
+  * gitlink:git-fsck-objects[1] to check the repository for errors.
 
-  * gitlink:git-prune[1] to garbage collect cruft in the
-    repository.
+  * gitlink:git-prune[1] to remove unused objects in the repository.
 
   * gitlink:git-repack[1] to pack loose objects for efficiency.
 
@@ -78,8 +62,8 @@ $ git repack -a -d <1>
 $ git prune
 ------------
 +
-<1> pack all the objects reachable from the refs into one pack
-and remove unneeded other packs
+<1> pack all the objects reachable from the refs into one pack,
+then remove the other packs.
 
 
 Individual Developer (Standalone)[[Individual Developer (Standalone)]]
@@ -93,9 +77,6 @@ following commands.
 
   * gitlink:git-log[1] to see what happened.
 
-  * gitlink:git-whatchanged[1] to find out where things have
-    come from.
-
   * gitlink:git-checkout[1] and gitlink:git-branch[1] to switch
     branches.
 
@@ -120,7 +101,7 @@ following commands.
 Examples
 ~~~~~~~~
 
-Extract a tarball and create a working tree and a new repository to keep track of it.::
+Use a tarball as a starting point for a new repository:
 +
 ------------
 $ tar zxf frotz.tar.gz
@@ -203,7 +184,7 @@ $ cd my2.6
 $ edit/compile/test; git commit -a -s <1>
 $ git format-patch origin <2>
 $ git pull <3>
-$ git whatchanged -p ORIG_HEAD.. arch/i386 include/asm-i386 <4>
+$ git log -p ORIG_HEAD.. arch/i386 include/asm-i386 <4>
 $ git pull git://git.kernel.org/pub/.../jgarzik/libata-dev.git ALL <5>
 $ git reset --hard ORIG_HEAD <6>
 $ git prune <7>
@@ -377,7 +358,7 @@ Run git-daemon to serve /pub/scm from inetd.::
 ------------
 $ grep git /etc/inetd.conf
 git	stream	tcp	nowait	nobody \
-  /usr/bin/git-daemon git-daemon --inetd --syslog --export-all /pub/scm
+  /usr/bin/git-daemon git-daemon --inetd --export-all /pub/scm
 ------------
 +
 The actual configuration line should be on one line.
@@ -397,7 +378,7 @@ service git
         wait            = no
         user            = nobody
         server          = /usr/bin/git-daemon
-        server_args     = --inetd --syslog --export-all --base-path=/pub/scm
+        server_args     = --inetd --export-all --base-path=/pub/scm
         log_on_failure  += USERID
 }
 ------------
diff --git a/Documentation/git-daemon.txt b/Documentation/git-daemon.txt
index d562232e5..4b2ea2df3 100644
--- a/Documentation/git-daemon.txt
+++ b/Documentation/git-daemon.txt
@@ -165,8 +165,7 @@ git-daemon as inetd server::
 +
 ------------------------------------------------
 	git stream tcp nowait nobody  /usr/bin/git-daemon
-		git-daemon --inetd --verbose
-		--syslog --export-all
+		git-daemon --inetd --verbose --export-all
 		/pub/foo /pub/bar
 ------------------------------------------------
 
@@ -179,8 +178,7 @@ git-daemon as inetd server for virtual hosts::
 +
 ------------------------------------------------
 	git stream tcp nowait nobody /usr/bin/git-daemon
-		git-daemon --inetd --verbose
-		--syslog --export-all
+		git-daemon --inetd --verbose --export-all
 		--interpolated-path=/pub/%H%D
 		/pub/www.example.org/software
 		/pub/www.example.com/software
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index 5d4257062..ed938aafb 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -122,14 +122,30 @@ blobs contained in a commit.
   your repository whose object name starts with dae86e.
 
 * An output from `git-describe`; i.e. a closest tag, followed by a
-  dash, a 'g', and an abbreviated object name.
+  dash, a `g`, and an abbreviated object name.
 
 * A symbolic ref name.  E.g. 'master' typically means the commit
   object referenced by $GIT_DIR/refs/heads/master.  If you
   happen to have both heads/master and tags/master, you can
   explicitly say 'heads/master' to tell git which one you mean.
+  When ambiguous, a `<name>` is disambiguated by taking the
+  first match in the following rules:
 
-* A suffix '@' followed by a date specification enclosed in a brace
+  . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
+    useful only for `HEAD`, `FETCH_HEAD` and `MERGE_HEAD`);
+
+  . otherwise, `$GIT_DIR/refs/<name>` if exists;
+
+  . otherwise, `$GIT_DIR/refs/tags/<name>` if exists;
+
+  . otherwise, `$GIT_DIR/refs/heads/<name>` if exists;
+
+  . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists;
+
+  . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists.
+
+* A ref followed by the suffix '@' with a date specification
+  enclosed in a brace
   pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
   second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value
   of the ref at a prior point in time.  This suffix may only be
@@ -146,8 +162,9 @@ blobs contained in a commit.
 * A suffix '{tilde}<n>' to a revision parameter means the commit
   object that is the <n>th generation grand-parent of the named
   commit object, following only the first parent.  I.e. rev~3 is
-  equivalent to rev{caret}{caret}{caret} which is equivalent to\
-  rev{caret}1{caret}1{caret}1.
+  equivalent to rev{caret}{caret}{caret} which is equivalent to
+  rev{caret}1{caret}1{caret}1.  See below for a illustration of
+  the usage of this form.
 
 * A suffix '{caret}' followed by an object type name enclosed in
   brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
diff --git a/combine-diff.c b/combine-diff.c
index 65c786807..466156fb4 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -489,6 +489,12 @@ static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long
 	printf(" -%lu,%lu", l0, l1-l0);
 }
 
+static int hunk_comment_line(const char *bol)
+{
+	int ch = *bol & 0xff;
+	return (isalpha(ch) || ch == '_' || ch == '$');
+}
+
 static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 		       int use_color)
 {
@@ -508,8 +514,13 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 		struct sline *sl = &sline[lno];
 		unsigned long hunk_end;
 		unsigned long rlines;
-		while (lno <= cnt && !(sline[lno].flag & mark))
+		const char *hunk_comment = NULL;
+
+		while (lno <= cnt && !(sline[lno].flag & mark)) {
+			if (hunk_comment_line(sline[lno].bol))
+				hunk_comment = sline[lno].bol;
 			lno++;
+		}
 		if (cnt < lno)
 			break;
 		else {
@@ -526,6 +537,22 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 			show_parent_lno(sline, lno, hunk_end, i);
 		printf(" +%lu,%lu ", lno+1, rlines);
 		for (i = 0; i <= num_parent; i++) putchar(combine_marker);
+
+		if (hunk_comment) {
+			int comment_end = 0;
+			for (i = 0; i < 40; i++) {
+				int ch = hunk_comment[i] & 0xff;
+				if (!ch || ch == '\n')
+					break;
+				if (!isspace(ch))
+				    comment_end = i;
+			}
+			if (comment_end)
+				putchar(' ');
+			for (i = 0; i < comment_end; i++)
+				putchar(hunk_comment[i]);
+		}
+
 		printf("%s\n", c_reset);
 		while (lno < hunk_end) {
 			struct lline *ll;
@@ -707,6 +734,8 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 		int use_color = opt->color_diff;
 		const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
 		const char *c_reset = diff_get_color(use_color, DIFF_RESET);
+		int added = 0;
+		int deleted = 0;
 
 		if (rev->loginfo)
 			show_log(rev, opt->msg_sep);
@@ -722,7 +751,10 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 		printf("..%s%s\n", abb, c_reset);
 
 		if (mode_differs) {
-			int added = !!elem->mode;
+			deleted = !elem->mode;
+
+			/* We say it was added if nobody had it */
+			added = !deleted;
 			for (i = 0; added && i < num_parent; i++)
 				if (elem->parent[i].status !=
 				    DIFF_STATUS_ADDED)
@@ -731,7 +763,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 				printf("%snew file mode %06o",
 				       c_meta, elem->mode);
 			else {
-				if (!elem->mode)
+				if (deleted)
 					printf("%sdeleted file ", c_meta);
 				printf("mode ");
 				for (i = 0; i < num_parent; i++) {
@@ -743,8 +775,14 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 			}
 			printf("%s\n", c_reset);
 		}
-		dump_quoted_path("--- a/", elem->path, c_meta, c_reset);
-		dump_quoted_path("+++ b/", elem->path, c_meta, c_reset);
+		if (added)
+			dump_quoted_path("--- /dev/", "null", c_meta, c_reset);
+		else
+			dump_quoted_path("--- a/", elem->path, c_meta, c_reset);
+		if (deleted)
+			dump_quoted_path("+++ /dev/", "null", c_meta, c_reset);
+		else
+			dump_quoted_path("+++ b/", elem->path, c_meta, c_reset);
 		dump_sline(sline, cnt, num_parent, opt->color_diff);
 	}
 	free(result);