documentation: add tutorial for first contribution

diff --git a/Documentation/technical/api-history-graph.txt b/Documentation/technical/api-history-graph.txt
index e9559790a32185b1d4ac8ae72881f4f63f082538..d0d1707c8c88560196eeb0d8bfe3be3362b682ea 100644 (file)
--- a/Documentation/technical/api-history-graph.txt
+++ b/Documentation/technical/api-history-graph.txt
@@ -11,9 +11,6 @@ Core functions:
 
 * `graph_init()` creates a new `struct git_graph`
 
-* `graph_release()` destroys a `struct git_graph`, and frees the memory
-  associated with it.
-
 * `graph_update()` moves the graph to a new commit.
 
 * `graph_next_line()` outputs the next line of the graph into a strbuf.  It
@@ -36,11 +33,11 @@ The following utility functions are wrappers around `graph_next_line()` and
 They can all be called with a NULL graph argument, in which case no graph
 output will be printed.
 
-* `graph_show_commit()` calls `graph_next_line()` until it returns non-zero.
-  This prints all graph lines up to, and including, the line containing this
-  commit.  Output is printed to stdout.  The last line printed does not contain
-  a terminating newline.  This should not be called if the commit line has
-  already been printed, or it will loop forever.
+* `graph_show_commit()` calls `graph_next_line()` and
+  `graph_is_commit_finished()` until one of them return non-zero.  This prints
+  all graph lines up to, and including, the line containing this commit.
+  Output is printed to stdout.  The last line printed does not contain a
+  terminating newline.
 
 * `graph_show_oneline()` calls `graph_next_line()` and prints the result to
   stdout.  The line printed does not contain a terminating newline.
@@ -83,7 +80,7 @@ Calling sequence
   it is invoked.
 
 * For each commit, call `graph_next_line()` repeatedly, until
-  `graph_is_commit_finished()` returns non-zero.  Each call go
+  `graph_is_commit_finished()` returns non-zero.  Each call to
   `graph_next_line()` will output a single line of the graph.  The resulting
   lines will not contain any newlines.  `graph_next_line()` returns 1 if the
   resulting line contains the current commit, or 0 if this is merely a line
@@ -118,7 +115,6 @@ struct commit *commit;
 struct git_graph *graph = graph_init(opts);
 
 while ((commit = get_revision(opts)) != NULL) {
-       graph_update(graph, commit);
        while (!graph_is_commit_finished(graph))
        {
                struct strbuf sb;
@@ -134,8 +130,6 @@ while ((commit = get_revision(opts)) != NULL) {
                        putchar(opts->diffopt.line_termination);
        }
 }
-
-graph_release(graph);
 ------------
 
 Sample output
@@ -148,22 +142,22 @@ outputting that information, if desired.
 ------------
 *
 *
-M
+*
 |\
 * |
 | | *
 | \ \
 |  \ \
-M-. \ \
+*-. \ \
 |\ \ \ \
 | | * | |
 | | | | | *
 | | | | | *
-| | | | | M
+| | | | | *
 | | | | | |\
 | | | | | | *
 | * | | | | |
-| | | | | M  \
+| | | | | *  \
 | | | | | |\  |
 | | | | * | | |
 | | | | * | | |