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>

cgit.c

@@ -250,6 +250,8 @@ static void querystring_cb(const char *name, const char *value)
 		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);
 	}
 }
 

cgit.h

@@ -145,6 +145,7 @@ struct cgit_query {
 	char *sort;
 	int showmsg;
 	int ssdiff;
+	int context;
 	char *vpath;
 };
 
@@ -274,7 +275,7 @@ 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,

shared.c

@@ -262,7 +262,8 @@ int filediff_cb(void *priv, mmbuffer_t *mb, int nbuf)
 
 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;
@@ -285,7 +286,7 @@ int cgit_diff_files(const unsigned char *old_sha1,
 	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;

ui-diff.c

@@ -127,7 +127,7 @@ static void inspect_filepair(struct diff_filepair *pair)
 	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;
@@ -288,7 +288,7 @@ static void filepair_cb(struct diff_filepair *pair)
 		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)

ui-log.c

@@ -33,7 +33,7 @@ void inspect_files(struct diff_filepair *pair)
 	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)

ui-patch.c

@@ -71,7 +71,7 @@ static void filepair_cb(struct diff_filepair *pair)
 		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");