bisect: add "git bisect help" subcommand to get a long usage string

diff --git a/help.c b/help.c
index e57a50ed59badbb968ce508b6c1802f1fcb68903..10298fb0a197f18008783214de11e424fbadb77d 100644 (file)
--- a/help.c
+++ b/help.c
@@ -8,6 +8,12 @@
 #include "exec_cmd.h"
 #include "common-cmds.h"
 #include "parse-options.h"
+#include "run-command.h"
+
+static struct man_viewer_list {
+       void (*exec)(const char *);
+       struct man_viewer_list *next;
+} *man_viewer_list;
 
 enum help_format {
        HELP_FORMAT_MAN,
@@ -24,6 +30,7 @@ static struct option builtin_help_options[] = {
                        HELP_FORMAT_WEB),
        OPT_SET_INT('i', "info", &help_format, "show info page",
                        HELP_FORMAT_INFO),
+       OPT_END(),
 };
 
 static const char * const builtin_help_usage[] = {
@@ -42,6 +49,102 @@ static enum help_format parse_help_format(const char *format)
        die("unrecognized help format '%s'", format);
 }
 
+static int check_emacsclient_version(void)
+{
+       struct strbuf buffer = STRBUF_INIT;
+       struct child_process ec_process;
+       const char *argv_ec[] = { "emacsclient", "--version", NULL };
+       int version;
+
+       /* emacsclient prints its version number on stderr */
+       memset(&ec_process, 0, sizeof(ec_process));
+       ec_process.argv = argv_ec;
+       ec_process.err = -1;
+       ec_process.stdout_to_stderr = 1;
+       if (start_command(&ec_process)) {
+               fprintf(stderr, "Failed to start emacsclient.\n");
+               return -1;
+       }
+       strbuf_read(&buffer, ec_process.err, 20);
+       close(ec_process.err);
+
+       /*
+        * Don't bother checking return value, because "emacsclient --version"
+        * seems to always exits with code 1.
+        */
+       finish_command(&ec_process);
+
+       if (prefixcmp(buffer.buf, "emacsclient")) {
+               fprintf(stderr, "Failed to parse emacsclient version.\n");
+               strbuf_release(&buffer);
+               return -1;
+       }
+
+       strbuf_remove(&buffer, 0, strlen("emacsclient"));
+       version = atoi(buffer.buf);
+
+       if (version < 22) {
+               fprintf(stderr,
+                       "emacsclient version '%d' too old (< 22).\n",
+                       version);
+               strbuf_release(&buffer);
+               return -1;
+       }
+
+       strbuf_release(&buffer);
+       return 0;
+}
+
+static void exec_woman_emacs(const char *page)
+{
+       if (!check_emacsclient_version()) {
+               /* This works only with emacsclient version >= 22. */
+               struct strbuf man_page = STRBUF_INIT;
+               strbuf_addf(&man_page, "(woman \"%s\")", page);
+               execlp("emacsclient", "emacsclient", "-e", man_page.buf, NULL);
+       }
+}
+
+static void exec_man_konqueror(const char *page)
+{
+       const char *display = getenv("DISPLAY");
+       if (display && *display) {
+               struct strbuf man_page = STRBUF_INIT;
+               strbuf_addf(&man_page, "man:%s(1)", page);
+               execlp("kfmclient", "kfmclient", "newTab", man_page.buf, NULL);
+       }
+}
+
+static void exec_man_man(const char *page)
+{
+       execlp("man", "man", page, NULL);
+}
+
+static void do_add_man_viewer(void (*exec)(const char *))
+{
+       struct man_viewer_list **p = &man_viewer_list;
+
+       while (*p)
+               p = &((*p)->next);
+       *p = xmalloc(sizeof(**p));
+       (*p)->next = NULL;
+       (*p)->exec = exec;
+}
+
+static int add_man_viewer(const char *value)
+{
+       if (!strcasecmp(value, "man"))
+               do_add_man_viewer(exec_man_man);
+       else if (!strcasecmp(value, "woman"))
+               do_add_man_viewer(exec_woman_emacs);
+       else if (!strcasecmp(value, "konqueror"))
+               do_add_man_viewer(exec_man_konqueror);
+       else
+               warning("'%s': unsupported man viewer.", value);
+
+       return 0;
+}
+
 static int git_help_config(const char *var, const char *value)
 {
        if (!strcmp(var, "help.format")) {
@@ -50,6 +153,11 @@ static int git_help_config(const char *var, const char *value)
                help_format = parse_help_format(value);
                return 0;
        }
+       if (!strcmp(var, "man.viewer")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               return add_man_viewer(value);
+       }
        return git_default_config(var, value);
 }
 
@@ -347,9 +455,16 @@ static void setup_man_path(void)
 
 static void show_man_page(const char *git_cmd)
 {
+       struct man_viewer_list *viewer;
        const char *page = cmd_to_page(git_cmd);
+
        setup_man_path();
-       execlp("man", "man", page, NULL);
+       for (viewer = man_viewer_list; viewer; viewer = viewer->next)
+       {
+               viewer->exec(page); /* will return when unable */
+       }
+       exec_man_man(page);
+       die("no man viewer handled the request");
 }
 
 static void show_info_page(const char *git_cmd)