ui-blob.c: Use a context structure in walk_tree()

Do not misuse global variables to save the context. Instead, use the
context pointer which was designed to share information between a
read_tree_fn and the caller.

This also prevents from potential misuse of the global pointers
match_path and matched_sha1 after the referenced values have been
overwritten on the stack.

Signed-off-by: Lukas Fleischer <cgit@cryptocrack.de>

1 files changed, 26 insertions, 16 deletions

diff --git a/ui-blob.c b/ui-blob.c
index d382ba3..c59fbcb 100644
--- a/ui-blob.c
+++ b/ui-blob.c
@@ -11,17 +11,22 @@
 #include "html.h"
 #include "ui-shared.h"
 
-static char *match_path;
-static unsigned char *matched_sha1;
-static int found_path;
+struct walk_tree_context {
+        char *match_path;
+        unsigned char *matched_sha1;
+        int found_path;
+};
 
 static int walk_tree(const unsigned char *sha1, const char *base, int baselen,
-        const char *pathname, unsigned mode, int stage, void *cbdata) {
-        if (strncmp(base, match_path, baselen)
-                || strcmp(match_path + baselen, pathname))
+        const char *pathname, unsigned mode, int stage, void *cbdata)
+{
+        struct walk_tree_context *walk_tree_ctx = cbdata;
+
+        if (strncmp(base, walk_tree_ctx->match_path, baselen)
+                || strcmp(walk_tree_ctx->match_path + baselen, pathname))
                 return READ_TREE_RECURSIVE;
-        memmove(matched_sha1, sha1, 20);
-        found_path = 1;
+        memmove(walk_tree_ctx->matched_sha1, sha1, 20);
+        walk_tree_ctx->found_path = 1;
         return 0;
 }
 
@@ -40,16 +45,19 @@ int cgit_print_file(char *path, const char *head)
                 .nr = 1,
                 .items = &path_items
         };
+        struct walk_tree_context walk_tree_ctx = {
+                .match_path = path,
+                .matched_sha1 = sha1,
+                .found_path = 0
+        };
+
         if (get_sha1(head, sha1))
                 return -1;
         type = sha1_object_info(sha1, &size);
         if (type == OBJ_COMMIT && path) {
                 commit = lookup_commit_reference(sha1);
-                match_path = path;
-                matched_sha1 = sha1;
-                found_path = 0;
-                read_tree_recursive(commit->tree, "", 0, 0, &paths, walk_tree, NULL);
-                if (!found_path)
+                read_tree_recursive(commit->tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
+                if (!walk_tree_ctx.found_path)
                         return -1;
                 type = sha1_object_info(sha1, &size);
         }
@@ -78,6 +86,10 @@ void cgit_print_blob(const char *hex, char *path, const char *head)
                 .nr = 1,
                 .items = &path_items
         };
+        struct walk_tree_context walk_tree_ctx = {
+                .match_path = path,
+                .matched_sha1 = sha1,
+        };
 
         if (hex) {
                 if (get_sha1_hex(hex, sha1)) {
@@ -95,9 +107,7 @@ void cgit_print_blob(const char *hex, char *path, const char *head)
 
         if ((!hex) && type == OBJ_COMMIT && path) {
                 commit = lookup_commit_reference(sha1);
-                match_path = path;
-                matched_sha1 = sha1;
-                read_tree_recursive(commit->tree, "", 0, 0, &paths, walk_tree, NULL);
+                read_tree_recursive(commit->tree, "", 0, 0, &paths, walk_tree, &walk_tree_ctx);
                 type = sha1_object_info(sha1,&size);
         }