On Thu, Mar 21, 2013 at 10:50:02AM -0700, Junio C Hamano wrote: > > Why could the test pass for you without it? It doesn't look like a > > bug that depended on uninitialized memory or something from the > > above observation.
It depends on uninitialized memory. For absolute paths, prefix is useless and I should have set the useful prefix length to zero, but I did not. Later in prefix_pathspec, I rely on this value to set nowildcard_len without checking if it's sane. The actual pathspec after prefix_pathspec is "src" (length of 3) but nowildcard_len is 5. In common_prefix_len(), I use nowildcard_len without sanity checks. So the code examines 's', 'r', 'c', '\0', '<random>'. In my case, '<random>' has never been '/'. I guess yours is '/' (which leads to wrong common prefix length). I've added an assert() to make sure nowildcard_len and prefix have sane values before exiting prefix_pathspec. This assert() chokes at t7300.8 for me. > The change made to prefix_path_gently() in this series is beyond > "disgusting", especially with the above fix-up. > > Sometimes it uses the original "len", sometimes it uses the fixed-up > *p_len (e.g. passes it down to normalize_path_copy_len()), and lets > normalize_path_copy_len() further update it, and thenit makes the > caller use the updated *p_len. > > Does the caller know what the value in *p_len _mean_ after this > function returns? Can it afford to lose the original length of the > prefix it saved in a variable, without getting confused? > > I think any change that turns a value-passed argument in the > existing code into modifiable pointer-to-variable in this series > should add in-code comment to describe what the variable mean upon > entry and after return, just like normalize_path_copy_len() that was > built out of the original normalize_path_copy(). I didn't look if > there are many others, or if this is the only one that is tricky. it > is tricky that even the original author of the patch got it wrong > X-<. > The author of the patch totally forgot that prefix has nothing to do with prefix. How about this? The prefix length is passed as value as before. A separate pointer is for passing back the actual prefix length. You can pull the actual patch from https://github.com/pclouds/git parse-pathspec which also includes all document bugs reported so far. -- 8< -- diff --git a/pathspec.c b/pathspec.c index 0771e48..126771c 100644 --- a/pathspec.c +++ b/pathspec.c @@ -205,7 +205,7 @@ static unsigned prefix_pathspec(struct pathspec_item *item, match = xstrdup(copyfrom); prefixlen = 0; } else { - match = prefix_path_gently(prefix, &prefixlen, copyfrom); + match = prefix_path_gently(prefix, prefixlen, &prefixlen, copyfrom); if (!match) die("%s: '%s' is outside repository", elt, copyfrom); } @@ -284,6 +284,10 @@ static unsigned prefix_pathspec(struct pathspec_item *item, no_wildcard(item->match + item->nowildcard_len + 1)) item->flags |= PATHSPEC_ONESTAR; } + + /* sanity checks, pathspec matchers assume these are sane */ + assert(item->nowildcard_len <= item->len && + item->prefix <= item->len); return magic; } @@ -315,7 +319,7 @@ static void NORETURN unsupported_magic(const char *pattern, n++; } /* - * We may want to substitue "this command" with a command + * We may want to substitute "this command" with a command * name. E.g. when add--interactive dies when running * "checkout -p" */ diff --git a/setup.c b/setup.c index e59146b..6cf2bc6 100644 --- a/setup.c +++ b/setup.c @@ -5,24 +5,37 @@ static int inside_git_dir = -1; static int inside_work_tree = -1; -char *prefix_path_gently(const char *prefix, int *p_len, const char *path) +/* + * Normalize "path", prepending the "prefix" for relative paths. If + * remaining_prefix is not NULL, return the actual prefix still + * remains in the path. For example, prefix = sub1/sub2/ and path is + * + * foo -> sub1/sub2/foo (full prefix) + * ../foo -> sub1/foo (remaining prefix is sub1/) + * ../../bar -> bar (no remaining prefix) + * ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix) + * `pwd`/../bar -> sub1/bar (no remaining prefix) + */ +char *prefix_path_gently(const char *prefix, int len, + int *remaining_prefix, const char *path) { const char *orig = path; char *sanitized; - int len = *p_len; if (is_absolute_path(orig)) { const char *temp = real_path(path); sanitized = xmalloc(len + strlen(temp) + 1); strcpy(sanitized, temp); - if (p_len) - *p_len = 0; + if (remaining_prefix) + *remaining_prefix = 0; } else { sanitized = xmalloc(len + strlen(path) + 1); if (len) memcpy(sanitized, prefix, len); strcpy(sanitized + len, path); + if (remaining_prefix) + *remaining_prefix = len; } - if (normalize_path_copy_len(sanitized, sanitized, p_len)) + if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) goto error_out; if (is_absolute_path(orig)) { size_t root_len, len, total; @@ -47,7 +60,7 @@ char *prefix_path_gently(const char *prefix, int *p_len, const char *path) char *prefix_path(const char *prefix, int len, const char *path) { - char *r = prefix_path_gently(prefix, &len, path); + char *r = prefix_path_gently(prefix, len, NULL, path); if (!r) die("'%s' is outside repository", path); return r; @@ -56,7 +69,7 @@ char *prefix_path(const char *prefix, int len, const char *path) int path_inside_repo(const char *prefix, const char *path) { int len = prefix ? strlen(prefix) : 0; - char *r = prefix_path_gently(prefix, &len, path); + char *r = prefix_path_gently(prefix, len, NULL, path); if (r) { free(r); return 1; -- 8< -- -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
