Add URL parameter 'context' for changing the number of context lines in diffs

The new ctx.qry.context variable is picked up by cgit_print_diff(), and
passed via cgit_diff_files() to Git's diff machinery.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

6 files changed, 11 insertions, 7 deletions

diff --git a/cgit.c b/cgit.c
index 2c3ad73..e9bafb5 100644
--- a/cgit.c
+++ b/cgit.c
@@ -221,64 +221,66 @@ static void querystring_cb(const char *name, const char *value)
 			value++;
 		ctx.qry.url = xstrdup(value);
 		cgit_parse_url(value);
 	} else if (!strcmp(name, "qt")) {
 		ctx.qry.grep = xstrdup(value);
 	} else if (!strcmp(name, "q")) {
 		ctx.qry.search = xstrdup(value);
 	} else if (!strcmp(name, "h")) {
 		ctx.qry.head = xstrdup(value);
 		ctx.qry.has_symref = 1;
 	} else if (!strcmp(name, "id")) {
 		ctx.qry.sha1 = xstrdup(value);
 		ctx.qry.has_sha1 = 1;
 	} else if (!strcmp(name, "id2")) {
 		ctx.qry.sha2 = xstrdup(value);
 		ctx.qry.has_sha1 = 1;
 	} else if (!strcmp(name, "ofs")) {
 		ctx.qry.ofs = atoi(value);
 	} else if (!strcmp(name, "path")) {
 		ctx.qry.path = trim_end(value, '/');
 	} else if (!strcmp(name, "name")) {
 		ctx.qry.name = xstrdup(value);
 	} else if (!strcmp(name, "mimetype")) {
 		ctx.qry.mimetype = xstrdup(value);
 	} else if (!strcmp(name, "s")){
 		ctx.qry.sort = xstrdup(value);
 	} else if (!strcmp(name, "showmsg")) {
 		ctx.qry.showmsg = atoi(value);
 	} else if (!strcmp(name, "period")) {
 		ctx.qry.period = xstrdup(value);
 	} else if (!strcmp(name, "ss")) {
 		ctx.qry.ssdiff = atoi(value);
+	} else if (!strcmp(name, "context")) {
+		ctx.qry.context = atoi(value);
 	}
 }
 
 char *xstrdupn(const char *str)
 {
 	return (str ? xstrdup(str) : NULL);
 }
 
 static void prepare_context(struct cgit_context *ctx)
 {
 	memset(ctx, 0, sizeof(*ctx));
 	ctx->cfg.agefile = "info/web/last-modified";
 	ctx->cfg.nocache = 0;
 	ctx->cfg.cache_size = 0;
 	ctx->cfg.cache_dynamic_ttl = 5;
 	ctx->cfg.cache_max_create_time = 5;
 	ctx->cfg.cache_repo_ttl = 5;
 	ctx->cfg.cache_root = CGIT_CACHE_ROOT;
 	ctx->cfg.cache_root_ttl = 5;
 	ctx->cfg.cache_scanrc_ttl = 15;
 	ctx->cfg.cache_static_ttl = -1;
 	ctx->cfg.css = "/cgit.css";
 	ctx->cfg.logo = "/cgit.png";
 	ctx->cfg.local_time = 0;
 	ctx->cfg.enable_tree_linenumbers = 1;
 	ctx->cfg.max_repo_count = 50;
 	ctx->cfg.max_commit_count = 50;
 	ctx->cfg.max_lock_attempts = 5;
 	ctx->cfg.max_msg_len = 80;
 	ctx->cfg.max_repodesc_len = 80;
 	ctx->cfg.max_blob_size = 0;
 	ctx->cfg.max_stats = 0;
diff --git a/cgit.h b/cgit.h
index f990b15..bb8f598 100644
--- a/cgit.h
+++ b/cgit.h
@@ -116,64 +116,65 @@ struct refinfo {
 		struct taginfo *tag;
 		struct commitinfo *commit;
 	};
 };
 
 struct reflist {
 	struct refinfo **refs;
 	int alloc;
 	int count;
 };
 
 struct cgit_query {
 	int has_symref;
 	int has_sha1;
 	char *raw;
 	char *repo;
 	char *page;
 	char *search;
 	char *grep;
 	char *head;
 	char *sha1;
 	char *sha2;
 	char *path;
 	char *name;
 	char *mimetype;
 	char *url;
 	char *period;
 	int   ofs;
 	int nohead;
 	char *sort;
 	int showmsg;
 	int ssdiff;
+	int context;
 	char *vpath;
 };
 
 struct cgit_config {
 	char *agefile;
 	char *cache_root;
 	char *clone_prefix;
 	char *css;
 	char *favicon;
 	char *footer;
 	char *head_include;
 	char *header;
 	char *index_header;
 	char *index_info;
 	char *logo;
 	char *logo_link;
 	char *module_link;
 	char *robots;
 	char *root_title;
 	char *root_desc;
 	char *root_readme;
 	char *script_name;
 	char *section;
 	char *virtual_root;
 	int cache_size;
 	int cache_dynamic_ttl;
 	int cache_max_create_time;
 	int cache_repo_ttl;
 	int cache_root_ttl;
 	int cache_scanrc_ttl;
 	int cache_static_ttl;
 	int embedded;
@@ -245,56 +246,56 @@ struct cgit_snapshot_format {
 	const char *mimetype;
 	write_archive_fn_t write_func;
 	int bit;
 };
 
 extern const char *cgit_version;
 
 extern struct cgit_repolist cgit_repolist;
 extern struct cgit_context ctx;
 extern const struct cgit_snapshot_format cgit_snapshot_formats[];
 
 extern struct cgit_repo *cgit_add_repo(const char *url);
 extern struct cgit_repo *cgit_get_repoinfo(const char *url);
 extern void cgit_repo_config_cb(const char *name, const char *value);
 
 extern int chk_zero(int result, char *msg);
 extern int chk_positive(int result, char *msg);
 extern int chk_non_negative(int result, char *msg);
 
 extern char *trim_end(const char *str, char c);
 extern char *strlpart(char *txt, int maxlen);
 extern char *strrpart(char *txt, int maxlen);
 
 extern void cgit_add_ref(struct reflist *list, struct refinfo *ref);
 extern int cgit_refs_cb(const char *refname, const unsigned char *sha1,
 			int flags, void *cb_data);
 
 extern void *cgit_free_commitinfo(struct commitinfo *info);
 
 extern int cgit_diff_files(const unsigned char *old_sha1,
 			   const unsigned char *new_sha1,
 			   unsigned long *old_size, unsigned long *new_size,
-			   int *binary, linediff_fn fn);
+			   int *binary, int context, linediff_fn fn);
 
 extern void cgit_diff_tree(const unsigned char *old_sha1,
 			   const unsigned char *new_sha1,
 			   filepair_fn fn, const char *prefix);
 
 extern void cgit_diff_commit(struct commit *commit, filepair_fn fn);
 
 extern char *fmt(const char *format,...);
 
 extern struct commitinfo *cgit_parse_commit(struct commit *commit);
 extern struct taginfo *cgit_parse_tag(struct tag *tag);
 extern void cgit_parse_url(const char *url);
 
 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_close_filter(struct cgit_filter *filter);
 
 extern int readfile(const char *path, char **buf, size_t *size);
 
 #endif /* CGIT_H */
diff --git a/shared.c b/shared.c
index 6e8f0ce..7cf1e59 100644
--- a/shared.c
+++ b/shared.c
@@ -233,88 +233,89 @@ int filediff_cb(void *priv, mmbuffer_t *mb, int nbuf)
 	for (i = 0; i < nbuf; i++) {
 		if (mb[i].ptr[mb[i].size-1] != '\n') {
 			/* Incomplete line */
 			diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
 			memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
 			buflen += mb[i].size;
 			continue;
 		}
 
 		/* we have a complete line */
 		if (!diffbuf) {
 			((linediff_fn)priv)(mb[i].ptr, mb[i].size);
 			continue;
 		}
 		diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
 		memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
 		((linediff_fn)priv)(diffbuf, buflen + mb[i].size);
 		free(diffbuf);
 		diffbuf = NULL;
 		buflen = 0;
 	}
 	if (diffbuf) {
 		((linediff_fn)priv)(diffbuf, buflen);
 		free(diffbuf);
 		diffbuf = NULL;
 		buflen = 0;
 	}
 	return 0;
 }
 
 int cgit_diff_files(const unsigned char *old_sha1,
 		    const unsigned char *new_sha1, unsigned long *old_size,
-		    unsigned long *new_size, int *binary, linediff_fn fn)
+		    unsigned long *new_size, int *binary, int context,
+		    linediff_fn fn)
 {
 	mmfile_t file1, file2;
 	xpparam_t diff_params;
 	xdemitconf_t emit_params;
 	xdemitcb_t emit_cb;
 
 	if (!load_mmfile(&file1, old_sha1) || !load_mmfile(&file2, new_sha1))
 		return 1;
 
 	*old_size = file1.size;
 	*new_size = file2.size;
 
 	if ((file1.ptr && buffer_is_binary(file1.ptr, file1.size)) ||
 	    (file2.ptr && buffer_is_binary(file2.ptr, file2.size))) {
 		*binary = 1;
 		return 0;
 	}
 
 	memset(&diff_params, 0, sizeof(diff_params));
 	memset(&emit_params, 0, sizeof(emit_params));
 	memset(&emit_cb, 0, sizeof(emit_cb));
 	diff_params.flags = XDF_NEED_MINIMAL;
-	emit_params.ctxlen = 3;
+	emit_params.ctxlen = context > 0 ? context : 3;
 	emit_params.flags = XDL_EMIT_FUNCNAMES;
 	emit_cb.outf = filediff_cb;
 	emit_cb.priv = fn;
 	xdl_diff(&file1, &file2, &diff_params, &emit_params, &emit_cb);
 	return 0;
 }
 
 void cgit_diff_tree(const unsigned char *old_sha1,
 		    const unsigned char *new_sha1,
 		    filepair_fn fn, const char *prefix)
 {
 	struct diff_options opt;
 	int ret;
 	int prefixlen;
 
 	diff_setup(&opt);
 	opt.output_format = DIFF_FORMAT_CALLBACK;
 	opt.detect_rename = 1;
 	opt.rename_limit = ctx.cfg.renamelimit;
 	DIFF_OPT_SET(&opt, RECURSIVE);
 	opt.format_callback = cgit_diff_tree_cb;
 	opt.format_callback_data = fn;
 	if (prefix) {
 		opt.nr_paths = 1;
 		opt.paths = &prefix;
 		prefixlen = strlen(prefix);
 		opt.pathlens = &prefixlen;
 	}
 	diff_setup_done(&opt);
 
 	if (old_sha1 && !is_null_sha1(old_sha1))
 		ret = diff_tree_sha1(old_sha1, new_sha1, "", &opt);
diff --git a/ui-diff.c b/ui-diff.c
index fb836df..d3a3b2c 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -98,65 +98,65 @@ static void print_fileinfo(struct fileinfo *info)
 	}
 	htmlf("%d", info->added + info->removed);
 	html("</td><td class='graph'>");
 	htmlf("<table summary='file diffstat' width='%d%%'><tr>", (max_changes > 100 ? 100 : max_changes));
 	htmlf("<td class='add' style='width: %.1f%%;'/>",
 	      info->added * 100.0 / max_changes);
 	htmlf("<td class='rem' style='width: %.1f%%;'/>",
 	      info->removed * 100.0 / max_changes);
 	htmlf("<td class='none' style='width: %.1f%%;'/>",
 	      (max_changes - info->removed - info->added) * 100.0 / max_changes);
 	html("</tr></table></td></tr>\n");
 }
 
 static void count_diff_lines(char *line, int len)
 {
 	if (line && (len > 0)) {
 		if (line[0] == '+')
 			lines_added++;
 		else if (line[0] == '-')
 			lines_removed++;
 	}
 }
 
 static void inspect_filepair(struct diff_filepair *pair)
 {
 	int binary = 0;
 	unsigned long old_size = 0;
 	unsigned long new_size = 0;
 	files++;
 	lines_added = 0;
 	lines_removed = 0;
 	cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size, &new_size,
-			&binary, count_diff_lines);
+			&binary, 0, count_diff_lines);
 	if (files >= slots) {
 		if (slots == 0)
 			slots = 4;
 		else
 			slots = slots * 2;
 		items = xrealloc(items, slots * sizeof(struct fileinfo));
 	}
 	items[files-1].status = pair->status;
 	hashcpy(items[files-1].old_sha1, pair->one->sha1);
 	hashcpy(items[files-1].new_sha1, pair->two->sha1);
 	items[files-1].old_mode = pair->one->mode;
 	items[files-1].new_mode = pair->two->mode;
 	items[files-1].old_path = xstrdup(pair->one->path);
 	items[files-1].new_path = xstrdup(pair->two->path);
 	items[files-1].added = lines_added;
 	items[files-1].removed = lines_removed;
 	items[files-1].old_size = old_size;
 	items[files-1].new_size = new_size;
 	items[files-1].binary = binary;
 	if (lines_added + lines_removed > max_changes)
 		max_changes = lines_added + lines_removed;
 	total_adds += lines_added;
 	total_rems += lines_removed;
 }
 
 void cgit_print_diffstat(const unsigned char *old_sha1,
 			 const unsigned char *new_sha1, const char *prefix)
 {
 	int i;
 
 	html("<div class='diffstat-header'>");
 	cgit_diff_link("Diffstat", NULL, NULL, ctx.qry.head, ctx.qry.sha1,
@@ -259,65 +259,65 @@ static void print_ssdiff_link()
 		else
 			cgit_diff_link("Side-by-side diff", NULL, NULL,
 				       ctx.qry.head, ctx.qry.sha1,
 				       ctx.qry.sha2, ctx.qry.path, 1);
 	}
 }
 
 static void filepair_cb(struct diff_filepair *pair)
 {
 	unsigned long old_size = 0;
 	unsigned long new_size = 0;
 	int binary = 0;
 	linediff_fn print_line_fn = print_line;
 
 	if (use_ssdiff) {
 		cgit_ssdiff_header_begin();
 		print_line_fn = cgit_ssdiff_line_cb;
 	}
 	header(pair->one->sha1, pair->one->path, pair->one->mode,
 	       pair->two->sha1, pair->two->path, pair->two->mode);
 	if (use_ssdiff)
 		cgit_ssdiff_header_end();
 	if (S_ISGITLINK(pair->one->mode) || S_ISGITLINK(pair->two->mode)) {
 		if (S_ISGITLINK(pair->one->mode))
 			print_line_fn(fmt("-Subproject %s", sha1_to_hex(pair->one->sha1)), 52);
 		if (S_ISGITLINK(pair->two->mode))
 			print_line_fn(fmt("+Subproject %s", sha1_to_hex(pair->two->sha1)), 52);
 		if (use_ssdiff)
 			cgit_ssdiff_footer();
 		return;
 	}
 	if (cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size,
-			    &new_size, &binary, print_line_fn))
+			    &new_size, &binary, ctx.qry.context, print_line_fn))
 		cgit_print_error("Error running diff");
 	if (binary) {
 		if (use_ssdiff)
 			html("<tr><td colspan='4'>Binary files differ</td></tr>");
 		else
 			html("Binary files differ");
 	}
 	if (use_ssdiff)
 		cgit_ssdiff_footer();
 }
 
 void cgit_print_diff(const char *new_rev, const char *old_rev, const char *prefix)
 {
 	enum object_type type;
 	unsigned long size;
 	struct commit *commit, *commit2;
 
 	if (!new_rev)
 		new_rev = ctx.qry.head;
 	get_sha1(new_rev, new_rev_sha1);
 	type = sha1_object_info(new_rev_sha1, &size);
 	if (type == OBJ_BAD) {
 		cgit_print_error(fmt("Bad object name: %s", new_rev));
 		return;
 	}
 	commit = lookup_commit_reference(new_rev_sha1);
 	if (!commit || parse_commit(commit))
 		cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(new_rev_sha1)));
 
 	if (old_rev)
 		get_sha1(old_rev, old_rev_sha1);
 	else if (commit->parents && commit->parents->item)
diff --git a/ui-log.c b/ui-log.c
index bfbe436..5eb5c81 100644
--- a/ui-log.c
+++ b/ui-log.c
@@ -4,65 +4,65 @@
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 #include "html.h"
 #include "ui-shared.h"
 
 int files, add_lines, rem_lines;
 
 void count_lines(char *line, int size)
 {
 	if (size <= 0)
 		return;
 
 	if (line[0] == '+')
 		add_lines++;
 
 	else if (line[0] == '-')
 		rem_lines++;
 }
 
 void inspect_files(struct diff_filepair *pair)
 {
 	unsigned long old_size = 0;
 	unsigned long new_size = 0;
 	int binary = 0;
 
 	files++;
 	if (ctx.repo->enable_log_linecount)
 		cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size,
-				&new_size, &binary, count_lines);
+				&new_size, &binary, 0, count_lines);
 }
 
 void show_commit_decorations(struct commit *commit)
 {
 	struct name_decoration *deco;
 	static char buf[1024];
 
 	buf[sizeof(buf) - 1] = 0;
 	deco = lookup_decoration(&name_decoration, &commit->object);
 	while (deco) {
 		if (!prefixcmp(deco->name, "refs/heads/")) {
 			strncpy(buf, deco->name + 11, sizeof(buf) - 1);
 			cgit_log_link(buf, NULL, "branch-deco", buf, NULL,
 				      ctx.qry.vpath, 0, NULL, NULL,
 				      ctx.qry.showmsg);
 		}
 		else if (!prefixcmp(deco->name, "tag: refs/tags/")) {
 			strncpy(buf, deco->name + 15, sizeof(buf) - 1);
 			cgit_tag_link(buf, NULL, "tag-deco", ctx.qry.head, buf);
 		}
 		else if (!prefixcmp(deco->name, "refs/tags/")) {
 			strncpy(buf, deco->name + 10, sizeof(buf) - 1);
 			cgit_tag_link(buf, NULL, "tag-deco", ctx.qry.head, buf);
 		}
 		else if (!prefixcmp(deco->name, "refs/remotes/")) {
 			strncpy(buf, deco->name + 13, sizeof(buf) - 1);
 			cgit_log_link(buf, NULL, "remote-deco", NULL,
 				      sha1_to_hex(commit->object.sha1),
 				      ctx.qry.vpath, 0, NULL, NULL,
 				      ctx.qry.showmsg);
 		}
 		else {
diff --git a/ui-patch.c b/ui-patch.c
index 25dc9fe..d13104c 100644
--- a/ui-patch.c
+++ b/ui-patch.c
@@ -42,65 +42,65 @@ static void header(unsigned char *sha1, char *path1, int mode1,
 	if (!subproject) {
 		abbrev1 = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
 		abbrev2 = xstrdup(find_unique_abbrev(sha2, DEFAULT_ABBREV));
 		htmlf("index %s..%s", abbrev1, abbrev2);
 		free(abbrev1);
 		free(abbrev2);
 		if (mode1 != 0 && mode2 != 0) {
 			htmlf(" %.6o", mode1);
 			if (mode2 != mode1)
 				htmlf("..%.6o", mode2);
 		}
 		htmlf("\n--- a/%s\n", path1);
 		htmlf("+++ b/%s\n", path2);
 	}
 }
 
 static void filepair_cb(struct diff_filepair *pair)
 {
 	unsigned long old_size = 0;
 	unsigned long new_size = 0;
 	int binary = 0;
 
 	header(pair->one->sha1, pair->one->path, pair->one->mode,
 	       pair->two->sha1, pair->two->path, pair->two->mode);
 	if (S_ISGITLINK(pair->one->mode) || S_ISGITLINK(pair->two->mode)) {
 		if (S_ISGITLINK(pair->one->mode))
 			print_line(fmt("-Subproject %s", sha1_to_hex(pair->one->sha1)), 52);
 		if (S_ISGITLINK(pair->two->mode))
 			print_line(fmt("+Subproject %s", sha1_to_hex(pair->two->sha1)), 52);
 		return;
 	}
 	if (cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size,
-			    &new_size, &binary, print_line))
+			    &new_size, &binary, 0, print_line))
 		html("Error running diff");
 	if (binary)
 		html("Binary files differ\n");
 }
 
 void cgit_print_patch(char *hex, const char *prefix)
 {
 	struct commit *commit;
 	struct commitinfo *info;
 	unsigned char sha1[20], old_sha1[20];
 	char *patchname;
 
 	if (!hex)
 		hex = ctx.qry.head;
 
 	if (get_sha1(hex, sha1)) {
 		cgit_print_error(fmt("Bad object id: %s", hex));
 		return;
 	}
 	commit = lookup_commit_reference(sha1);
 	if (!commit) {
 		cgit_print_error(fmt("Bad commit reference: %s", hex));
 		return;
 	}
 	info = cgit_parse_commit(commit);
 
 	if (commit->parents && commit->parents->item)
 		hashcpy(old_sha1, commit->parents->item->object.sha1);
 	else
 		hashclr(old_sha1);
 
 	patchname = fmt("%s.patch", sha1_to_hex(sha1));