thodg/libgit2

diff --git a/include/git2/errors.h b/include/git2/errors.h
index 17a7010..0406c16 100644
--- a/include/git2/errors.h
+++ b/include/git2/errors.h
@@ -21,98 +21,25 @@ typedef enum {
 	GIT_SUCCESS = 0,
 	GIT_ERROR = -1,
 
-	/** Input was not a properly formatted Git object id. */
-	GIT_ENOTOID = -2,
-
 	/** Input does not exist in the scope searched. */
 	GIT_ENOTFOUND = -3,
 
-	/** Not enough space available. */
-	GIT_ENOMEM = -4,
-
-	/** Consult the OS error information. */
-	GIT_EOSERR = -5,
-
-	/** The specified object is of invalid type */
-	GIT_EOBJTYPE = -6,
-
-	/** The specified repository is invalid */
-	GIT_ENOTAREPO = -7,
-
-	/** The object type is invalid or doesn't match */
-	GIT_EINVALIDTYPE = -8,
-
-	/** The object cannot be written because it's missing internal data */
-	GIT_EMISSINGOBJDATA = -9,
-
-	/** The packfile for the ODB is corrupted */
-	GIT_EPACKCORRUPTED = -10,
-
-	/** Failed to acquire or release a file lock */
-	GIT_EFLOCKFAIL = -11,
-
-	/** The Z library failed to inflate/deflate an object's data */
-	GIT_EZLIB = -12,
-
-	/** The queried object is currently busy */
-	GIT_EBUSY = -13,
-
-	/** The index file is not backed up by an existing repository */
-	GIT_EBAREINDEX = -14,
-
-	/** The name of the reference is not valid */
-	GIT_EINVALIDREFNAME = -15,
-
-	/** The specified reference has its data corrupted */
-	GIT_EREFCORRUPTED = -16,
-
-	/** The specified symbolic reference is too deeply nested */
-	GIT_ETOONESTEDSYMREF = -17,
-
-	/** The pack-refs file is either corrupted or its format is not currently supported */
-	GIT_EPACKEDREFSCORRUPTED = -18,
-
-	/** The path is invalid */
-	GIT_EINVALIDPATH = -19,
-
-	/** The revision walker is empty; there are no more commits left to iterate */
-	GIT_EREVWALKOVER = -20,
-
-	/** The state of the reference is not valid */
-	GIT_EINVALIDREFSTATE = -21,
-
-	/** This feature has not been implemented yet */
-	GIT_ENOTIMPLEMENTED = -22,
-
 	/** A reference with this name already exists */
 	GIT_EEXISTS = -23,
 
 	/** The given integer literal is too large to be parsed */
 	GIT_EOVERFLOW = -24,
 
-	/** The given literal is not a valid number */
-	GIT_ENOTNUM = -25,
-
-	/** Streaming error */
-	GIT_ESTREAM = -26,
-
-	/** invalid arguments to function */
-	GIT_EINVALIDARGS = -27,
-
-	/** The specified object has its data corrupted */
-	GIT_EOBJCORRUPTED = -28,
-
 	/** The given short oid is ambiguous */
 	GIT_EAMBIGUOUS = -29,
 
 	/** Skip and passthrough the given ODB backend */
 	GIT_EPASSTHROUGH = -30,
 
-	/** The path pattern and string did not match */
-	GIT_ENOMATCH = -31,
-
 	/** The buffer is too short to satisfy the request */
 	GIT_ESHORTBUFFER = -32,
+
+	GIT_EREVWALKOVER = -33,
 } git_error_t;
 
 typedef struct {
@@ -138,44 +65,17 @@ typedef enum {
 } git_error_class;
 
 /**
- * Return a detailed error string with the latest error
- * that occurred in the library.
- * @deprecated This will be replaced in the new error handling
- * @return a string explaining the error
- */
-GIT_EXTERN(const char *) git_lasterror(void);
-
-/**
- * strerror() for the Git library
- *
- * Get a string description for a given error code.
- * NOTE: This method will be eventually deprecated in favor
- * of the new `git_lasterror`.
- *
- * @deprecated This will be replaced in the new error handling
- * @param num The error code to explain
- * @return a string explaining the error code
- */
-GIT_EXTERN(const char *) git_strerror(int num);
-
-/**
- * Clear the latest library error
- * @deprecated This will be replaced in the new error handling
- */
-GIT_EXTERN(void) git_clearerror(void);
-
-/**
  * Return the last `git_error` object that was generated for the
  * current thread or NULL if no error has occurred.
  *
  * @return A git_error object.
  */
-GIT_EXTERN(const git_error *) git_error_last(void);
+GIT_EXTERN(const git_error *) giterr_last(void);
 
 /**
  * Clear the last library error that occurred for this thread.
  */
-GIT_EXTERN(void) git_error_clear(void);
+GIT_EXTERN(void) giterr_clear(void);
 
 /** @} */
 GIT_END_DECL
diff --git a/include/git2/refspec.h b/include/git2/refspec.h
index 3acf114..28afe65 100644
--- a/include/git2/refspec.h
+++ b/include/git2/refspec.h
@@ -7,6 +7,7 @@
 #ifndef INCLUDE_git_refspec_h__
 #define INCLUDE_git_refspec_h__
 
+#include "common.h"
 #include "types.h"
 
 /**
@@ -35,14 +36,13 @@ const char *git_refspec_src(const git_refspec *refspec);
 const char *git_refspec_dst(const git_refspec *refspec);
 
 /**
- * Match a refspec's source descriptor with a reference name
+ * Check if a refspec's source descriptor matches a reference 
  *
  * @param refspec the refspec
  * @param refname the name of the reference to check
- * @return GIT_SUCCESS on successful match; GIT_ENOMACH on match
- * failure or an error code on other failure
+ * @return 1 if the refspec matches, 0 otherwise
  */
-int git_refspec_src_match(const git_refspec *refspec, const char *refname);
+int git_refspec_src_matches(const git_refspec *refspec, const char *refname);
 
 /**
  * Transform a reference to its target following the refspec's rules
diff --git a/src/config.c b/src/config.c
index 4c97192..0ab0cd4 100644
--- a/src/config.c
+++ b/src/config.c
@@ -59,8 +59,7 @@ int git_config_new(git_config **out)
 	git_config *cfg;
 
 	cfg = git__malloc(sizeof(git_config));
-	if (cfg == NULL)
-		return GIT_ENOMEM;
+	GITERR_CHECK_ALLOC(cfg);
 
 	memset(cfg, 0x0, sizeof(git_config));
 
@@ -221,7 +220,7 @@ int git_config_parse_bool(int *out, const char *value)
 		return 0;
 	}
 
-	return GIT_EINVALIDTYPE;
+	return -1;
 }
 
 static int parse_int64(int64_t *out, const char *value)
diff --git a/src/crlf.c b/src/crlf.c
index 8fe588a..b495d2d 100644
--- a/src/crlf.c
+++ b/src/crlf.c
@@ -216,8 +216,7 @@ int git_filter_add__crlf_to_odb(git_vector *filters, git_repository *repo, const
 	/* If we're good, we create a new filter object and push it
 	 * into the filters array */
 	filter = git__malloc(sizeof(struct crlf_filter));
-	if (filter == NULL)
-		return GIT_ENOMEM;
+	GITERR_CHECK_ALLOC(filter);
 
 	filter->f.apply = &crlf_apply_to_odb;
 	filter->f.do_free = NULL;
diff --git a/src/delta-apply.c b/src/delta-apply.c
index c8c662f..d3be084 100644
--- a/src/delta-apply.c
+++ b/src/delta-apply.c
@@ -61,8 +61,9 @@ int git__delta_apply(
 		return -1;
 	}
 
-	if ((res_dp = git__malloc(res_sz + 1)) == NULL)
-		return GIT_ENOMEM;
+	res_dp = git__malloc(res_sz + 1);
+	GITERR_CHECK_ALLOC(res_dp);
+
 	res_dp[res_sz] = '\0';
 	out->data = res_dp;
 	out->len = res_sz;
diff --git a/src/diff.c b/src/diff.c
index b21dfaf..b845f9e 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -35,10 +35,10 @@ static bool diff_path_matches_pathspec(git_diff_list *diff, const char *path)
 		return true;
 
 	git_vector_foreach(&diff->pathspec, i, match) {
-		int result = git__fnmatch(match->pattern, path, 0);
+		int result = p_fnmatch(match->pattern, path, 0);
 
 		/* if we didn't match, look for exact dirname prefix match */
-		if (result == GIT_ENOMATCH &&
+		if (result == FNM_NOMATCH &&
 			(match->flags & GIT_ATTR_FNMATCH_HASWILD) == 0 &&
 			strncmp(path, match->pattern, match->length) == 0 &&
 			path[match->length] == '/')
@@ -46,9 +46,6 @@ static bool diff_path_matches_pathspec(git_diff_list *diff, const char *path)
 
 		if (result == 0)
 			return (match->flags & GIT_ATTR_FNMATCH_NEGATIVE) ? false : true;
-
-		if (result != GIT_ENOMATCH)
-			giterr_clear();
 	}
 
 	return false;
diff --git a/src/errors.c b/src/errors.c
index 7a6bbd6..f708519 100644
--- a/src/errors.c
+++ b/src/errors.c
@@ -9,105 +9,6 @@
 #include "posix.h"
 #include <stdarg.h>
 
-static struct {
-	int num;
-	const char *str;
-} error_codes[] = {
-	{GIT_ERROR, "Unspecified error"},
-	{GIT_ENOTOID, "Input was not a properly formatted Git object id."},
-	{GIT_ENOTFOUND, "Object does not exist in the scope searched."},
-	{GIT_ENOMEM, "Not enough space available."},
-	{GIT_EOSERR, "Consult the OS error information."},
-	{GIT_EOBJTYPE, "The specified object is of invalid type"},
-	{GIT_EOBJCORRUPTED, "The specified object has its data corrupted"},
-	{GIT_ENOTAREPO, "The specified repository is invalid"},
-	{GIT_EINVALIDTYPE, "The object or config variable type is invalid or doesn't match"},
-	{GIT_EMISSINGOBJDATA, "The object cannot be written that because it's missing internal data"},
-	{GIT_EPACKCORRUPTED, "The packfile for the ODB is corrupted"},
-	{GIT_EFLOCKFAIL, "Failed to adquire or release a file lock"},
-	{GIT_EZLIB, "The Z library failed to inflate/deflate an object's data"},
-	{GIT_EBUSY, "The queried object is currently busy"},
-	{GIT_EINVALIDPATH, "The path is invalid"},
-	{GIT_EBAREINDEX, "The index file is not backed up by an existing repository"},
-	{GIT_EINVALIDREFNAME, "The name of the reference is not valid"},
-	{GIT_EREFCORRUPTED, "The specified reference has its data corrupted"},
-	{GIT_ETOONESTEDSYMREF, "The specified symbolic reference is too deeply nested"},
-	{GIT_EPACKEDREFSCORRUPTED, "The pack-refs file is either corrupted of its format is not currently supported"},
-	{GIT_EINVALIDPATH, "The path is invalid" },
-	{GIT_EREVWALKOVER, "The revision walker is empty; there are no more commits left to iterate"},
-	{GIT_EINVALIDREFSTATE, "The state of the reference is not valid"},
-	{GIT_ENOTIMPLEMENTED, "This feature has not been implemented yet"},
-	{GIT_EEXISTS, "A reference with this name already exists"},
-	{GIT_EOVERFLOW, "The given integer literal is too large to be parsed"},
-	{GIT_ENOTNUM, "The given literal is not a valid number"},
-	{GIT_EAMBIGUOUS, "The given oid prefix is ambiguous"},
-};
-
-const char *git_strerror(int num)
-{
-	size_t i;
-
-	if (num == GIT_EOSERR)
-		return strerror(errno);
-	for (i = 0; i < ARRAY_SIZE(error_codes); i++)
-		if (num == error_codes[i].num)
-			return error_codes[i].str;
-
-	return "Unknown error";
-}
-
-#define ERROR_MAX_LEN 1024
-
-void git___rethrow(const char *msg, ...)
-{
-	char new_error[ERROR_MAX_LEN];
-	char *last_error;
-	char *old_error = NULL;
-
-	va_list va;
-
-	last_error = GIT_GLOBAL->error.last;
-
-	va_start(va, msg);
-	vsnprintf(new_error, ERROR_MAX_LEN, msg, va);
-	va_end(va);
-
-	old_error = git__strdup(last_error);
-
-	snprintf(last_error, ERROR_MAX_LEN, "%s \n	- %s", new_error, old_error);
-
-	git__free(old_error);
-}
-
-void git___throw(const char *msg, ...)
-{
-	va_list va;
-
-	va_start(va, msg);
-	vsnprintf(GIT_GLOBAL->error.last, ERROR_MAX_LEN, msg, va);
-	va_end(va);
-}
-
-const char *git_lasterror(void)
-{
-	char *last_error = GIT_GLOBAL->error.last;
-
-	if (!last_error[0]) {
-		const git_error *err = git_error_last();
-		if (err != NULL)
-			return err->message;
-		return NULL;
-	}
-
-	return last_error;
-}
-
-void git_clearerror(void)
-{
-	char *last_error = GIT_GLOBAL->error.last;
-	last_error[0] = '\0';
-}
-
 /********************************************
  * New error handling
  ********************************************/
@@ -198,13 +99,8 @@ void giterr_clear(void)
 	GIT_GLOBAL->last_error = NULL;
 }
 
-const git_error *git_error_last(void)
+const git_error *giterr_last(void)
 {
 	return GIT_GLOBAL->last_error;
 }
 
-void git_error_clear(void)
-{
-	giterr_clear();
-}
-
diff --git a/src/fetch.c b/src/fetch.c
index 6fe1b56..1944bd0 100644
--- a/src/fetch.c
+++ b/src/fetch.c
@@ -29,21 +29,13 @@ struct filter_payload {
 static int filter_ref__cb(git_remote_head *head, void *payload)
 {
 	struct filter_payload *p = payload;
-	int ret;
 
 	if (!p->found_head && strcmp(head->name, GIT_HEAD_FILE) == 0) {
 		p->found_head = 1;
 	} else {
 		/* If it doesn't match the refpec, we don't want it */
-		ret = git_refspec_src_match(p->spec, head->name);
-
-		if (ret == GIT_ENOMATCH)
+		if (!git_refspec_src_matches(p->spec, head->name))
 			return 0;
-
-		if (ret < GIT_SUCCESS) {
-			giterr_set(GITERR_NET, "Error matching remote ref name");
-			return -1;
-		}
 	}
 
 	/* If we have the object, mark it so we don't ask for it */
diff --git a/src/filter.c b/src/filter.c
index d6c2e1c..73fe83e 100644
--- a/src/filter.c
+++ b/src/filter.c
@@ -92,11 +92,11 @@ int git_filters_load(git_vector *filters, git_repository *repo, const char *path
 	if (mode == GIT_FILTER_TO_ODB) {
 		/* Load the CRLF cleanup filter when writing to the ODB */
 		error = git_filter_add__crlf_to_odb(filters, repo, path);
-		if (error < GIT_SUCCESS)
+		if (error < 0)
 			return error;
 	} else {
 		giterr_set(GITERR_INVALID, "Worktree filters are not implemented yet");
-		return GIT_ENOTIMPLEMENTED;
+		return -1;
 	}
 
 	return (int)filters->length;
@@ -135,7 +135,7 @@ int git_filters_apply(git_buf *dest, git_buf *source, git_vector *filters)
 	/* Pre-grow the destination buffer to more or less the size
 	 * we expect it to have */
 	if (git_buf_grow(dest, git_buf_len(source)) < 0)
-		return GIT_ENOMEM;
+		return -1;
 
 	for (i = 0; i < filters->length; ++i) {
 		git_filter *filter = git_vector_get(filters, i);
@@ -153,7 +153,7 @@ int git_filters_apply(git_buf *dest, git_buf *source, git_vector *filters)
 			src = dst;
 
 		if (git_buf_oom(dbuffer[dst]))
-			return GIT_ENOMEM;
+			return -1;
 	}
 
 	/* Ensure that the output ends up in dbuffer[1] (i.e. the dest) */
diff --git a/src/object.c b/src/object.c
index 979fb40..8e8eac4 100644
--- a/src/object.c
+++ b/src/object.c
@@ -62,8 +62,7 @@ static int create_object(git_object **object_out, git_otype type)
 	case GIT_OBJ_BLOB:
 	case GIT_OBJ_TREE:
 		object = git__malloc(git_object__size(type));
-		if (object == NULL)
-			return GIT_ENOMEM;
+		GITERR_CHECK_ALLOC(object);
 		memset(object, 0x0, git_object__size(type));
 		break;
 
diff --git a/src/refspec.c b/src/refspec.c
index bec770a..ee4d3a1 100644
--- a/src/refspec.c
+++ b/src/refspec.c
@@ -10,6 +10,7 @@
 #include "common.h"
 #include "refspec.h"
 #include "util.h"
+#include "posix.h"
 
 int git_refspec_parse(git_refspec *refspec, const char *str)
 {
@@ -52,9 +53,12 @@ const char *git_refspec_dst(const git_refspec *refspec)
 	return refspec == NULL ? NULL : refspec->dst;
 }
 
-int git_refspec_src_match(const git_refspec *refspec, const char *refname)
+int git_refspec_src_matches(const git_refspec *refspec, const char *refname)
 {
-	return (refspec == NULL || refspec->src == NULL) ? GIT_ENOMATCH : git__fnmatch(refspec->src, refname, 0);
+	if (refspec == NULL || refspec->src == NULL)
+		return false;
+
+	return (p_fnmatch(refspec->src, refname, 0) == 0);
 }
 
 int git_refspec_transform(char *out, size_t outlen, const git_refspec *spec, const char *name)
diff --git a/src/revwalk.c b/src/revwalk.c
index c62bb4e..1b53978 100644
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -486,7 +486,7 @@ static int push_glob_cb(const char *refname, void *data_)
 {
 	struct push_cb_data *data = (struct push_cb_data *)data_;
 
-	if (!git__fnmatch(data->glob, refname, 0))
+	if (!p_fnmatch(data->glob, refname, 0))
 		return push_ref(data->walk, refname, data->hide);
 
 	return 0;
diff --git a/src/tag.c b/src/tag.c
index ff22bf7..aa549fd 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -420,7 +420,7 @@ int git_tag_list_match(git_strarray *tag_names, const char *pattern, git_reposit
 	assert(tag_names && repo && pattern);
 
 	if (git_vector_init(&taglist, 8, NULL) < GIT_SUCCESS)
-		return GIT_ENOMEM;
+		return -1;
 
 	filter.taglist = &taglist;
 	filter.pattern = pattern;
diff --git a/src/transport.c b/src/transport.c
index 0c88e44..bc4248d 100644
--- a/src/transport.c
+++ b/src/transport.c
@@ -66,8 +66,10 @@ int git_transport_new(git_transport **out, const char *url)
 
 	fn = transport_find_fn(url);
 
-	if (fn == NULL)
-		return git__throw(GIT_EINVALIDARGS, "Unsupported URL or non-existent path");
+	if (fn == NULL) {
+		giterr_set(GITERR_NET, "Unsupported URL protocol");
+		return -1;
+	}
 
 	error = fn(&transport);
 	if (error < GIT_SUCCESS)
diff --git a/src/transports/git.c b/src/transports/git.c
index 31bc21c..c51b167 100644
--- a/src/transports/git.c
+++ b/src/transports/git.c
@@ -72,7 +72,7 @@ static int gen_proto(git_buf *request, const char *cmd, const char *url)
 	git_buf_putc(request, '\0');
 
 	if (git_buf_oom(request))
-		return GIT_ENOMEM;
+		return -1;
 
 	return 0;
 }
diff --git a/src/transports/http.c b/src/transports/http.c
index 3690f3d..1b2b5eb 100644
--- a/src/transports/http.c
+++ b/src/transports/http.c
@@ -78,7 +78,7 @@ static int gen_request(git_buf *buf, const char *url, const char *host, const ch
 	git_buf_puts(buf, "\r\n");
 
 	if (git_buf_oom(buf))
-		return GIT_ENOMEM;
+		return -1;
 
 	return 0;
 }
@@ -174,13 +174,13 @@ static int on_headers_complete(http_parser *parser)
 	if (t->content_type == NULL) {
 		t->content_type = git__strdup(git_buf_cstr(buf));
 		if (t->content_type == NULL)
-			return t->error = GIT_ENOMEM;
+			return t->error = -1;
 	}
 
 	git_buf_clear(buf);
 	git_buf_printf(buf, "application/x-git-%s-advertisement", t->service);
 	if (git_buf_oom(buf))
-		return t->error = GIT_ENOMEM;
+		return t->error = -1;
 
 	if (strcmp(t->content_type, git_buf_cstr(buf)))
 		return t->error = -1;
diff --git a/src/tree-cache.c b/src/tree-cache.c
index 9baa06a..ebc2c68 100644
--- a/src/tree-cache.c
+++ b/src/tree-cache.c
@@ -82,24 +82,19 @@ static int read_tree_internal(git_tree_cache **out,
 	git_tree_cache *tree = NULL;
 	const char *name_start, *buffer;
 	int count;
-	int error = GIT_SUCCESS;
 	size_t name_len;
 
 	buffer = name_start = *buffer_in;
 
-	if ((buffer = memchr(buffer, '\0', buffer_end - buffer)) == NULL) {
-		error = GIT_EOBJCORRUPTED;
-		goto cleanup;
-	}
+	if ((buffer = memchr(buffer, '\0', buffer_end - buffer)) == NULL)
+		goto corrupted;
 
-	if (++buffer >= buffer_end) {
-		error = GIT_EOBJCORRUPTED;
-		goto cleanup;
-	}
+	if (++buffer >= buffer_end)
+		goto corrupted;
 
 	name_len = strlen(name_start);
-	if ((tree = git__malloc(sizeof(git_tree_cache) + name_len + 1)) == NULL)
-		return GIT_ENOMEM;
+	tree = git__malloc(sizeof(git_tree_cache) + name_len + 1);
+	GITERR_CHECK_ALLOC(tree);
 
 	memset(tree, 0x0, sizeof(git_tree_cache));
 	tree->parent = parent;
@@ -109,39 +104,28 @@ static int read_tree_internal(git_tree_cache **out,
 	tree->name[name_len] = '\0';
 
 	/* Blank-terminated ASCII decimal number of entries in this tree */
-	if (git__strtol32(&count, buffer, &buffer, 10) < GIT_SUCCESS || count < -1) {
-		error = GIT_EOBJCORRUPTED;
-		goto cleanup;
-	}
+	if (git__strtol32(&count, buffer, &buffer, 10) < 0 || count < -1)
+		goto corrupted;
 
 	tree->entries = count;
 
-	if (*buffer != ' ' || ++buffer >= buffer_end) {
-		error = GIT_EOBJCORRUPTED;
-		goto cleanup;
-	}
+	if (*buffer != ' ' || ++buffer >= buffer_end)
+		goto corrupted;
 
 	 /* Number of children of the tree, newline-terminated */
-	if (git__strtol32(&count, buffer, &buffer, 10) < GIT_SUCCESS ||
-		count < 0) {
-		error = GIT_EOBJCORRUPTED;
-		goto cleanup;
-	}
+	if (git__strtol32(&count, buffer, &buffer, 10) < 0 || count < 0)
+		goto corrupted;
 
 	tree->children_count = count;
 
-	if (*buffer != '\n' || ++buffer > buffer_end) {
-		error = GIT_EOBJCORRUPTED;
-		goto cleanup;
-	}
+	if (*buffer != '\n' || ++buffer > buffer_end)
+		goto corrupted;
 
 	/* The SHA1 is only there if it's not invalidated */
 	if (tree->entries >= 0) {
 		/* 160-bit SHA-1 for this tree and it's children */
-		if (buffer + GIT_OID_RAWSZ > buffer_end) {
-			error = GIT_EOBJCORRUPTED;
-			goto cleanup;
-		}
+		if (buffer + GIT_OID_RAWSZ > buffer_end)
+			goto corrupted;
 
 		git_oid_fromraw(&tree->oid, (const unsigned char *)buffer);
 		buffer += GIT_OID_RAWSZ;
@@ -150,40 +134,39 @@ static int read_tree_internal(git_tree_cache **out,
 	/* Parse children: */
 	if (tree->children_count > 0) {
 		unsigned int i;
-		int err;
 
 		tree->children = git__malloc(tree->children_count * sizeof(git_tree_cache *));
-		if (tree->children == NULL)
-			goto cleanup;
+		GITERR_CHECK_ALLOC(tree->children);
 
 		for (i = 0; i < tree->children_count; ++i) {
-			err = read_tree_internal(&tree->children[i], &buffer, buffer_end, tree);
-
-			if (err < GIT_SUCCESS)
-				goto cleanup;
+			if (read_tree_internal(&tree->children[i], &buffer, buffer_end, tree) < 0)
+				return -1;
 		}
 	}
 
 	*buffer_in = buffer;
 	*out = tree;
-	return GIT_SUCCESS;
+	return 0;
 
- cleanup:
+ corrupted:
 	git_tree_cache_free(tree);
-	return error;
+	giterr_set(GITERR_INDEX, "Corruped TREE extension in index");
+	return -1;
 }
 
 int git_tree_cache_read(git_tree_cache **tree, const char *buffer, size_t buffer_size)
 {
 	const char *buffer_end = buffer + buffer_size;
-	int error;
 
-	error = read_tree_internal(tree, &buffer, buffer_end, NULL);
+	if (read_tree_internal(tree, &buffer, buffer_end, NULL) < 0)
+		return -1;
 
-	if (buffer < buffer_end)
-		return GIT_EOBJCORRUPTED;
+	if (buffer < buffer_end) {
+		giterr_set(GITERR_INDEX, "Corruped TREE extension in index (unexpected trailing data)");
+		return -1;
+	}
 
-	return error;
+	return 0;
 }
 
 void git_tree_cache_free(git_tree_cache *tree)
diff --git a/src/tree.c b/src/tree.c
index 09ed1a3..7e2bfc1 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -741,7 +741,7 @@ int git_tree_walk(git_tree *tree, git_treewalk_cb callback, int mode, void *payl
 
 		case GIT_TREEWALK_PRE:
 			tree_error("Preorder tree walking is still not implemented");
-			return GIT_ENOTIMPLEMENTED;
+			return -1;
 
 		default:
 			giterr_set(GITERR_INVALID, "Invalid walking mode for tree walk");
diff --git a/src/util.c b/src/util.c
index 2cf7b15..20a627e 100644
--- a/src/util.c
+++ b/src/util.c
@@ -60,22 +60,6 @@ int git_strarray_copy(git_strarray *tgt, const git_strarray *src)
 	return 0;
 }
 
-int git__fnmatch(const char *pattern, const char *name, int flags)
-{
-	int ret;
-
-	ret = p_fnmatch(pattern, name, flags);
-	switch (ret) {
-	case 0:
-		return 0;
-	case FNM_NOMATCH:
-		return GIT_ENOMATCH;
-	default:
-		giterr_set(GITERR_OS, "Error trying to match path");
-		return -1;
-	}
-}
-
 int git__strtol64(int64_t *result, const char *nptr, const char **endptr, int base)
 {
 	const char *p;
diff --git a/src/util.h b/src/util.h
index 1fee9a7..a768001 100644
--- a/src/util.h
+++ b/src/util.h
@@ -105,8 +105,6 @@ GIT_INLINE(const char *) git__next_line(const char *s)
 	return s;
 }
 
-extern int git__fnmatch(const char *pattern, const char *name, int flags);
-
 extern void git__tsort(void **dst, size_t size, int (*cmp)(const void *, const void *));
 
 /**
diff --git a/tests-clar/clar_libgit2.h b/tests-clar/clar_libgit2.h
index 4d338ef..63bc703 100644
--- a/tests-clar/clar_libgit2.h
+++ b/tests-clar/clar_libgit2.h
@@ -13,9 +13,9 @@
  * return error codes!
  */
 #define cl_git_pass(expr) do { \
-	git_clearerror(); \
-	if ((expr) != GIT_SUCCESS) \
-		clar__assert(0, __FILE__, __LINE__, "Function call failed: " #expr, git_lasterror(), 1); \
+	giterr_clear(); \
+	if ((expr) != 0) \
+		clar__assert(0, __FILE__, __LINE__, "Function call failed: " #expr, giterr_last()->message, 1); \
 	} while(0)
 
 /**
diff --git a/tests-clar/core/errors.c b/tests-clar/core/errors.c
index 78f811c..0be3e7a 100644
--- a/tests-clar/core/errors.c
+++ b/tests-clar/core/errors.c
@@ -3,46 +3,30 @@
 #include "util.h"
 #include "posix.h"
 
-#ifdef git__throw
-void test_core_errors__old_school(void)
-{
-	git_clearerror();
-	cl_assert(git_lasterror() == NULL);
-
-	cl_assert(git_strerror(GIT_ENOTFOUND) != NULL);
-
-	git__throw(GIT_ENOTFOUND, "My Message");
-	cl_assert(git_lasterror() != NULL);
-	cl_assert(git__prefixcmp(git_lasterror(), "My Message") == 0);
-	git_clearerror();
-}
-#endif
-
-#ifdef GITERR_CHECK_ALLOC
 void test_core_errors__new_school(void)
 {
 	char *str_in_error;
 
-	git_error_clear();
-	cl_assert(git_error_last() == NULL);
+	giterr_clear();
+	cl_assert(giterr_last() == NULL);
 
 	giterr_set_oom(); /* internal fn */
 
-	cl_assert(git_error_last() != NULL);
-	cl_assert(git_error_last()->klass == GITERR_NOMEMORY);
-	str_in_error = strstr(git_error_last()->message, "memory");
+	cl_assert(giterr_last() != NULL);
+	cl_assert(giterr_last()->klass == GITERR_NOMEMORY);
+	str_in_error = strstr(giterr_last()->message, "memory");
 	cl_assert(str_in_error != NULL);
 
-	git_error_clear();
+	giterr_clear();
 
 	giterr_set(GITERR_REPOSITORY, "This is a test"); /* internal fn */
 
-	cl_assert(git_error_last() != NULL);
-	str_in_error = strstr(git_error_last()->message, "This is a test");
+	cl_assert(giterr_last() != NULL);
+	str_in_error = strstr(giterr_last()->message, "This is a test");
 	cl_assert(str_in_error != NULL);
 
-	git_error_clear();
-	cl_assert(git_error_last() == NULL);
+	giterr_clear();
+	cl_assert(giterr_last() == NULL);
 
 	do {
 		struct stat st;
@@ -52,26 +36,25 @@ void test_core_errors__new_school(void)
 	} while (false);
 	giterr_set(GITERR_OS, "stat failed"); /* internal fn */
 
-	cl_assert(git_error_last() != NULL);
-	str_in_error = strstr(git_error_last()->message, "stat failed");
+	cl_assert(giterr_last() != NULL);
+	str_in_error = strstr(giterr_last()->message, "stat failed");
 	cl_assert(str_in_error != NULL);
 	cl_assert(git__prefixcmp(str_in_error, "stat failed: ") == 0);
 	cl_assert(strlen(str_in_error) > strlen("stat failed: "));
 
 #ifdef GIT_WIN32
-	git_error_clear();
+	giterr_clear();
 
 	/* The MSDN docs use this to generate a sample error */
 	cl_assert(GetProcessId(NULL) == 0);
 	giterr_set(GITERR_OS, "GetProcessId failed"); /* internal fn */
 
-	cl_assert(git_error_last() != NULL);
-	str_in_error = strstr(git_error_last()->message, "GetProcessId failed");
+	cl_assert(giterr_last() != NULL);
+	str_in_error = strstr(giterr_last()->message, "GetProcessId failed");
 	cl_assert(str_in_error != NULL);
 	cl_assert(git__prefixcmp(str_in_error, "GetProcessId failed: ") == 0);
 	cl_assert(strlen(str_in_error) > strlen("GetProcessId failed: "));
 #endif
 
-	git_error_clear();
+	giterr_clear();
 }
-#endif
diff --git a/tests-clar/network/remotes.c b/tests-clar/network/remotes.c
index 9d414c9..766a461 100644
--- a/tests-clar/network/remotes.c
+++ b/tests-clar/network/remotes.c
@@ -101,8 +101,8 @@ void test_network_remotes__save(void)
 
 void test_network_remotes__fnmatch(void)
 {
-	cl_git_pass(git_refspec_src_match(_refspec, "refs/heads/master"));
-	cl_git_pass(git_refspec_src_match(_refspec, "refs/heads/multi/level/branch"));
+	cl_assert(git_refspec_src_matches(_refspec, "refs/heads/master"));
+	cl_assert(git_refspec_src_matches(_refspec, "refs/heads/multi/level/branch"));
 }
 
 void test_network_remotes__transform(void)
diff --git a/tests-clar/object/tree/frompath.c b/tests-clar/object/tree/frompath.c
index d4075c0..ea0add3 100644
--- a/tests-clar/object/tree/frompath.c
+++ b/tests-clar/object/tree/frompath.c
@@ -43,7 +43,7 @@ static void assert_tree_from_path(git_tree *root, const char *path, int expected
 static void assert_tree_from_path_klass(git_tree *root, const char *path, int expected_result, const char *expected_raw_oid)
 {
 	assert_tree_from_path(root, path, GIT_ERROR, expected_raw_oid);
-	cl_assert(git_error_last()->klass == expected_result);
+	cl_assert(giterr_last()->klass == expected_result);
 }
 
 void test_object_tree_frompath__retrieve_tree_from_path_to_treeentry(void)