[PATCH 3/6] filter: pass extra arguments via cgit_open_filter

[John Keeping]

This avoids poking into the filter data structure at various points in
the code.  We rely on the fact that the number of arguments is fixed
based on the filter type (set in cgit_new_filter) and that the call
sites all know which filter type they're using.

Signed-off-by: John Keeping <john at keeping.me.uk>
---
 cgit.h        |  3 ++-
 filter.c      | 35 ++++++++++++++++++++++++-----------
 ui-repolist.c | 10 +++-------
 ui-summary.c  | 13 ++++++-------
 ui-tree.c     |  7 +++----
 5 files changed, 38 insertions(+), 30 deletions(-)

diff --git a/cgit.h b/cgit.h
index a72c503..e6e7715 100644
--- a/cgit.h
+++ b/cgit.h
@@ -59,6 +59,7 @@ typedef enum {
 struct cgit_filter {
 	char *cmd;
 	char **argv;
+	int extra_args;
 	int old_stdout;
 	int pipe_fh[2];
 	int pid;
@@ -342,7 +343,7 @@ extern const char *cgit_repobasename(const char *reponame);
 
 extern int cgit_parse_snapshots_mask(const char *str);
 
-extern int cgit_open_filter(struct cgit_filter *filter);
+extern int cgit_open_filter(struct cgit_filter *filter, ...);
 extern int cgit_close_filter(struct cgit_filter *filter);
 extern struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype);
 
diff --git a/filter.c b/filter.c
index f4ee9ac..d8c0116 100644
--- a/filter.c
+++ b/filter.c
@@ -13,8 +13,16 @@
 #include <string.h>
 #include <stdlib.h>
 
-int cgit_open_filter(struct cgit_filter *filter)
+int cgit_open_filter(struct cgit_filter *filter, ...)
 {
+	int i;
+	va_list ap;
+
+	va_start(ap, filter);
+	for (i = 0; i < filter->extra_args; i++)
+		filter->argv[i+1] = va_arg(ap, char *);
+	va_end(ap);
+
 	filter->old_stdout = chk_positive(dup(STDOUT_FILENO),
 		"Unable to duplicate STDOUT");
 	chk_zero(pipe(filter->pipe_fh), "Unable to create pipe to subprocess");
@@ -36,45 +44,50 @@ int cgit_open_filter(struct cgit_filter *filter)
 
 int cgit_close_filter(struct cgit_filter *filter)
 {
-	int exit_status;
+	int i, exit_status;
 
 	chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO),
 		"Unable to restore STDOUT");
 	close(filter->old_stdout);
 	if (filter->pid < 0)
-		return 0;
+		goto done;
 	waitpid(filter->pid, &exit_status, 0);
 	if (WIFEXITED(exit_status) && !WEXITSTATUS(exit_status))
-		return 0;
+		goto done;
 	die("Subprocess %s exited abnormally", filter->cmd);
+
+done:
+	for (i = 0; i < filter->extra_args; i++)
+		filter->argv[i+1] = NULL;
+	return 0;
+
 }
 
 struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
 {
 	struct cgit_filter *f;
 	int args_size = 0;
-	int extra_args;
 
 	if (!cmd || !cmd[0])
 		return NULL;
 
+	f = xmalloc(sizeof(struct cgit_filter));
+	memset(f, 0, sizeof(struct cgit_filter));
+
 	switch (filtertype) {
 		case SOURCE:
 		case ABOUT:
-			extra_args = 1;
+			f->extra_args = 1;
 			break;
 
 		case COMMIT:
 		default:
-			extra_args = 0;
+			f->extra_args = 0;
 			break;
 	}
-	
-	f = xmalloc(sizeof(struct cgit_filter));
-	memset(f, 0, sizeof(struct cgit_filter));
 
 	f->cmd = xstrdup(cmd);
-	args_size = (2 + extra_args) * sizeof(char *);
+	args_size = (2 + f->extra_args) * sizeof(char *);
 	f->argv = xmalloc(args_size);
 	memset(f->argv, 0, args_size);
 	f->argv[0] = f->cmd;
diff --git a/ui-repolist.c b/ui-repolist.c
index d4ee279..f622a01 100644
--- a/ui-repolist.c
+++ b/ui-repolist.c
@@ -331,13 +331,9 @@ void cgit_print_site_readme()
 {
 	if (!ctx.cfg.root_readme)
 		return;
-	if (ctx.cfg.about_filter) {
-		ctx.cfg.about_filter->argv[1] = ctx.cfg.root_readme;
-		cgit_open_filter(ctx.cfg.about_filter);
-	}
+	if (ctx.cfg.about_filter)
+		cgit_open_filter(ctx.cfg.about_filter, ctx.cfg.root_readme);
 	html_include(ctx.cfg.root_readme);
-	if (ctx.cfg.about_filter) {
+	if (ctx.cfg.about_filter)
 		cgit_close_filter(ctx.cfg.about_filter);
-		ctx.cfg.about_filter->argv[1] = NULL;
-	}
 }
diff --git a/ui-summary.c b/ui-summary.c
index 63a5a75..725f3ab 100644
--- a/ui-summary.c
+++ b/ui-summary.c
@@ -151,18 +151,17 @@ void cgit_print_repo_readme(char *path)
 	 * filesystem, while applying the about-filter.
 	 */
 	html("<div id='summary'>");
-	if (ctx.repo->about_filter) {
-		ctx.repo->about_filter->argv[1] = filename;
-		cgit_open_filter(ctx.repo->about_filter);
-	}
+	if (ctx.repo->about_filter)
+		cgit_open_filter(ctx.repo->about_filter, filename);
+
 	if (ref)
 		cgit_print_file(filename, ref, 1);
 	else
 		html_include(filename);
-	if (ctx.repo->about_filter) {
+
+	if (ctx.repo->about_filter)
 		cgit_close_filter(ctx.repo->about_filter);
-		ctx.repo->about_filter->argv[1] = NULL;
-	}
+
 	html("</div>");
 	if (free_filename)
 		free(filename);
diff --git a/ui-tree.c b/ui-tree.c
index 5ae3926..e4c3d22 100644
--- a/ui-tree.c
+++ b/ui-tree.c
@@ -45,13 +45,12 @@ static void print_text_buffer(const char *name, char *buf, unsigned long size)
 	}
 
 	if (ctx.repo->source_filter) {
+		char *filter_arg = xstrdup(name);
 		html("<td class='lines'><pre><code>");
-		ctx.repo->source_filter->argv[1] = xstrdup(name);
-		cgit_open_filter(ctx.repo->source_filter);
+		cgit_open_filter(ctx.repo->source_filter, filter_arg);
 		html_raw(buf, size);
 		cgit_close_filter(ctx.repo->source_filter);
-		free(ctx.repo->source_filter->argv[1]);
-		ctx.repo->source_filter->argv[1] = NULL;
+		free(filter_arg);
 		html("</code></pre></td></tr></table>\n");
 		return;
 	}
-- 
1.8.5.226.g0d60d77