thodg/libgit2

diff --git a/src/config.c b/src/config.c
index d0e439b..8338da0 100644
--- a/src/config.c
+++ b/src/config.c
@@ -7,13 +7,15 @@
 
 #include "config.h"
 
-#include "sysdir.h"
 #include "git2/config.h"
 #include "git2/sys/config.h"
-#include "vector.h"
+
 #include "buf_text.h"
 #include "config_backend.h"
+#include "regexp.h"
+#include "sysdir.h"
 #include "transaction.h"
+#include "vector.h"
 #if GIT_WIN32
 # include <windows.h>
 #endif
@@ -345,7 +347,7 @@ typedef struct {
 	git_config_iterator parent;
 	git_config_iterator *current;
 	const git_config *cfg;
-	p_regex_t regex;
+	git_regexp regex;
 	size_t i;
 } all_iter;
 
@@ -423,7 +425,7 @@ static int all_iter_glob_next(git_config_entry **entry, git_config_iterator *_it
 	 */
 	while ((error = all_iter_next(entry, _iter)) == 0) {
 		/* skip non-matching keys if regexp was provided */
-		if (p_regexec(&iter->regex, (*entry)->name, 0, NULL, 0) != 0)
+		if (git_regexp_match(&iter->regex, (*entry)->name) != 0)
 			continue;
 
 		/* and simply return if we like the entry's name */
@@ -447,7 +449,7 @@ static void all_iter_glob_free(git_config_iterator *_iter)
 {
 	all_iter *iter = (all_iter *) _iter;
 
-	p_regfree(&iter->regex);
+	git_regexp_dispose(&iter->regex);
 	all_iter_free(_iter);
 }
 
@@ -480,8 +482,7 @@ int git_config_iterator_glob_new(git_config_iterator **out, const git_config *cf
 	iter = git__calloc(1, sizeof(all_iter));
 	GIT_ERROR_CHECK_ALLOC(iter);
 
-	if ((result = p_regcomp(&iter->regex, regexp, P_REG_EXTENDED)) != 0) {
-		git_error_set_regex(&iter->regex, result);
+	if ((result = git_regexp_compile(&iter->regex, regexp, 0)) < 0) {
 		git__free(iter);
 		return -1;
 	}
@@ -510,18 +511,13 @@ int git_config_backend_foreach_match(
 {
 	git_config_entry *entry;
 	git_config_iterator* iter;
-	p_regex_t regex;
+	git_regexp regex;
 	int error = 0;
 
 	assert(backend && cb);
 
-	if (regexp != NULL) {
-		if ((error = p_regcomp(&regex, regexp, P_REG_EXTENDED)) != 0) {
-			git_error_set_regex(&regex, error);
-			p_regfree(&regex);
-			return -1;
-		}
-	}
+	if (regexp && git_regexp_compile(&regex, regexp, 0) < 0)
+		return -1;
 
 	if ((error = backend->iterator(&iter, backend)) < 0) {
 		iter = NULL;
@@ -530,7 +526,7 @@ int git_config_backend_foreach_match(
 
 	while (!(iter->next(&entry, iter) < 0)) {
 		/* skip non-matching keys if regexp was provided */
-		if (regexp && p_regexec(&regex, entry->name, 0, NULL, 0) != 0)
+		if (regexp && git_regexp_match(&regex, entry->name) != 0)
 			continue;
 
 		/* abort iterator on non-zero return value */
@@ -541,7 +537,7 @@ int git_config_backend_foreach_match(
 	}
 
 	if (regexp != NULL)
-		p_regfree(&regex);
+		git_regexp_dispose(&regex);
 
 	iter->free(iter);
 
@@ -981,7 +977,7 @@ typedef struct {
 	git_config_iterator parent;
 	git_config_iterator *iter;
 	char *name;
-	p_regex_t regex;
+	git_regexp regex;
 	int have_regex;
 } multivar_iter;
 
@@ -997,7 +993,7 @@ static int multivar_iter_next(git_config_entry **entry, git_config_iterator *_it
 		if (!iter->have_regex)
 			return 0;
 
-		if (p_regexec(&iter->regex, (*entry)->value, 0, NULL, 0) == 0)
+		if (git_regexp_match(&iter->regex, (*entry)->value) == 0)
 			return 0;
 	}
 
@@ -1012,7 +1008,7 @@ void multivar_iter_free(git_config_iterator *_iter)
 
 	git__free(iter->name);
 	if (iter->have_regex)
-		p_regfree(&iter->regex);
+		git_regexp_dispose(&iter->regex);
 	git__free(iter);
 }
 
@@ -1032,13 +1028,8 @@ int git_config_multivar_iterator_new(git_config_iterator **out, const git_config
 		goto on_error;
 
 	if (regexp != NULL) {
-		error = p_regcomp(&iter->regex, regexp, P_REG_EXTENDED);
-		if (error != 0) {
-			git_error_set_regex(&iter->regex, error);
-			error = -1;
-			p_regfree(&iter->regex);
+		if ((error = git_regexp_compile(&iter->regex, regexp, 0)) < 0)
 			goto on_error;
-		}
 
 		iter->have_regex = 1;
 	}
diff --git a/src/config_file.c b/src/config_file.c
index 849096d..bf770c9 100644
--- a/src/config_file.c
+++ b/src/config_file.c
@@ -18,6 +18,7 @@
 #include "config_entries.h"
 #include "config_parse.h"
 #include "filebuf.h"
+#include "regexp.h"
 #include "strmap.h"
 #include "sysdir.h"
 #include "wildmatch.h"
@@ -61,7 +62,7 @@ typedef struct {
 
 static int config_read(git_config_entries *entries, const git_repository *repo, config_file *file, git_config_level_t level, int depth);
 static int config_read_buffer(git_config_entries *entries, const git_repository *repo, config_file *file, git_config_level_t level, int depth, const char *buf, size_t buflen);
-static int config_write(config_file_backend *cfg, const char *orig_key, const char *key, const p_regex_t *preg, const char *value);
+static int config_write(config_file_backend *cfg, const char *orig_key, const char *key, const git_regexp *preg, const char *value);
 static char *escape_value(const char *ptr);
 
 /**
@@ -350,21 +351,17 @@ static int config_set_multivar(
 	git_config_backend *cfg, const char *name, const char *regexp, const char *value)
 {
 	config_file_backend *b = GIT_CONTAINER_OF(cfg, config_file_backend, parent);
-	char *key;
-	p_regex_t preg;
+	git_regexp preg;
 	int result;
+	char *key;
 
 	assert(regexp);
 
 	if ((result = git_config__normalize_name(name, &key)) < 0)
 		return result;
 
-	result = p_regcomp(&preg, regexp, P_REG_EXTENDED);
-	if (result != 0) {
-		git_error_set_regex(&preg, result);
-		result = -1;
+	if ((result = git_regexp_compile(&preg, regexp, 0)) < 0)
 		goto out;
-	}
 
 	/* If we do have it, set call config_write() and reload */
 	if ((result = config_write(b, name, key, &preg, value)) < 0)
@@ -372,7 +369,7 @@ static int config_set_multivar(
 
 out:
 	git__free(key);
-	p_regfree(&preg);
+	git_regexp_dispose(&preg);
 
 	return result;
 }
@@ -412,7 +409,7 @@ static int config_delete_multivar(git_config_backend *cfg, const char *name, con
 	config_file_backend *b = GIT_CONTAINER_OF(cfg, config_file_backend, parent);
 	git_config_entries *entries = NULL;
 	git_config_entry *entry = NULL;
-	p_regex_t preg = { 0 };
+	git_regexp preg = GIT_REGEX_INIT;
 	char *key = NULL;
 	int result;
 
@@ -430,11 +427,8 @@ static int config_delete_multivar(git_config_backend *cfg, const char *name, con
 		goto out;
 	}
 
-	if ((result = p_regcomp(&preg, regexp, P_REG_EXTENDED)) != 0) {
-		git_error_set_regex(&preg, result);
-		result = -1;
+	if ((result = git_regexp_compile(&preg, regexp, 0)) < 0)
 		goto out;
-	}
 
 	if ((result = config_write(b, name, key, &preg, NULL)) < 0)
 		goto out;
@@ -442,7 +436,7 @@ static int config_delete_multivar(git_config_backend *cfg, const char *name, con
 out:
 	git_config_entries_free(entries);
 	git__free(key);
-	p_regfree(&preg);
+	git_regexp_dispose(&preg);
 	return result;
 }
 
@@ -928,7 +922,7 @@ struct write_data {
 	const char *section;
 	const char *orig_name;
 	const char *name;
-	const p_regex_t *preg;
+	const git_regexp *preg;
 	const char *value;
 };
 
@@ -1033,7 +1027,7 @@ static int write_on_variable(
 
 	/* If we have a regex to match the value, see if it matches */
 	if (has_matched && write_data->preg != NULL)
-		has_matched = (p_regexec(write_data->preg, var_value, 0, NULL, 0) == 0);
+		has_matched = (git_regexp_match(write_data->preg, var_value) == 0);
 
 	/* If this isn't the name/value we're looking for, simply dump the
 	 * existing data back out and continue on.
@@ -1094,7 +1088,8 @@ static int write_on_eof(
 /*
  * This is pretty much the parsing, except we write out anything we don't have
  */
-static int config_write(config_file_backend *cfg, const char *orig_key, const char *key, const p_regex_t *preg, const char* value)
+static int config_write(config_file_backend *cfg, const char *orig_key, const char *key, const git_regexp *preg, const char* value)
+
 {
 	char *orig_section = NULL, *section = NULL, *orig_name, *name, *ldot;
 	git_buf buf = GIT_BUF_INIT, contents = GIT_BUF_INIT;
diff --git a/src/diff_driver.c b/src/diff_driver.c
index 6919e4e..831d326 100644
--- a/src/diff_driver.c
+++ b/src/diff_driver.c
@@ -15,6 +15,7 @@
 #include "map.h"
 #include "buf_text.h"
 #include "config.h"
+#include "regexp.h"
 #include "repository.h"
 
 typedef enum {
@@ -25,7 +26,7 @@ typedef enum {
 } git_diff_driver_t;
 
 typedef struct {
-	p_regex_t re;
+	git_regexp re;
 	int flags;
 } git_diff_driver_pattern;
 
@@ -39,7 +40,7 @@ struct git_diff_driver {
 	uint32_t binary_flags;
 	uint32_t other_flags;
 	git_array_t(git_diff_driver_pattern) fn_patterns;
-	p_regex_t  word_pattern;
+	git_regexp  word_pattern;
 	char name[GIT_FLEX_ARRAY];
 };
 
@@ -113,7 +114,7 @@ static int diff_driver_add_patterns(
 		if (error < 0)
 			break;
 
-		if ((error = p_regcomp(&pat->re, buf.ptr, regex_flags)) != 0) {
+		if ((error = git_regexp_compile(&pat->re, buf.ptr, regex_flags)) != 0) {
 			/*
 			 * TODO: issue a warning
 			 */
@@ -130,7 +131,7 @@ static int diff_driver_add_patterns(
 
 static int diff_driver_xfuncname(const git_config_entry *entry, void *payload)
 {
-	return diff_driver_add_patterns(payload, entry->value, P_REG_EXTENDED);
+	return diff_driver_add_patterns(payload, entry->value, 0);
 }
 
 static int diff_driver_funcname(const git_config_entry *entry, void *payload)
@@ -205,16 +206,12 @@ static int git_diff_driver_builtin(
 
 	if (ddef->fns &&
 		(error = diff_driver_add_patterns(
-			drv, ddef->fns, ddef->flags | P_REG_EXTENDED)) < 0)
+			drv, ddef->fns, ddef->flags)) < 0)
 		goto done;
 
 	if (ddef->words &&
-		(error = p_regcomp(
-			&drv->word_pattern, ddef->words, ddef->flags | P_REG_EXTENDED)))
-	{
-		error = git_error_set_regex(&drv->word_pattern, error);
+	    (error = git_regexp_compile(&drv->word_pattern, ddef->words, ddef->flags)) < 0)
 		goto done;
-	}
 
 	if ((error = git_strmap_set(reg->drivers, drv->name, drv)) < 0)
 		goto done;
@@ -316,11 +313,10 @@ static int git_diff_driver_load(
 		goto done;
 	if (!ce || !ce->value)
 		/* no diff.<driver>.wordregex, so just continue */;
-	else if (!(error = p_regcomp(&drv->word_pattern, ce->value, P_REG_EXTENDED)))
+	else if (!(error = git_regexp_compile(&drv->word_pattern, ce->value, 0)))
 		found_driver = true;
 	else {
 		/* TODO: warn about bad regex instead of failure */
-		error = git_error_set_regex(&drv->word_pattern, error);
 		goto done;
 	}
 
@@ -400,10 +396,10 @@ void git_diff_driver_free(git_diff_driver *driver)
 		return;
 
 	for (i = 0; i < git_array_size(driver->fn_patterns); ++i)
-		p_regfree(& git_array_get(driver->fn_patterns, i)->re);
+		git_regexp_dispose(& git_array_get(driver->fn_patterns, i)->re);
 	git_array_clear(driver->fn_patterns);
 
-	p_regfree(&driver->word_pattern);
+	git_regexp_dispose(&driver->word_pattern);
 
 	git__free(driver);
 }
@@ -451,19 +447,19 @@ static int diff_context_line__pattern_match(
 	git_diff_driver *driver, git_buf *line)
 {
 	size_t i, maxi = git_array_size(driver->fn_patterns);
-	p_regmatch_t pmatch[2];
+	git_regmatch pmatch[2];
 
 	for (i = 0; i < maxi; ++i) {
 		git_diff_driver_pattern *pat = git_array_get(driver->fn_patterns, i);
 
-		if (!p_regexec(&pat->re, line->ptr, 2, pmatch, 0)) {
+		if (!git_regexp_search(&pat->re, line->ptr, 2, pmatch)) {
 			if (pat->flags & REG_NEGATE)
 				return false;
 
 			/* use pmatch data to trim line data */
-			i = (pmatch[1].rm_so >= 0) ? 1 : 0;
-			git_buf_consume(line, git_buf_cstr(line) + pmatch[i].rm_so);
-			git_buf_truncate(line, pmatch[i].rm_eo - pmatch[i].rm_so);
+			i = (pmatch[1].start >= 0) ? 1 : 0;
+			git_buf_consume(line, git_buf_cstr(line) + pmatch[i].start);
+			git_buf_truncate(line, pmatch[i].end - pmatch[i].start);
 			git_buf_rtrim(line);
 
 			return true;
diff --git a/src/revparse.c b/src/revparse.c
index 4bde0d7..2618b38 100644
--- a/src/revparse.c
+++ b/src/revparse.c
@@ -12,6 +12,7 @@
 #include "buffer.h"
 #include "tree.h"
 #include "refdb.h"
+#include "regexp.h"
 
 #include "git2.h"
 
@@ -42,7 +43,7 @@ static int maybe_abbrev(git_object** out, git_repository *repo, const char *spec
 	return maybe_sha_or_abbrev(out, repo, spec, speclen);
 }
 
-static int build_regex(p_regex_t *regex, const char *pattern)
+static int build_regex(git_regexp *regex, const char *pattern)
 {
 	int error;
 
@@ -51,13 +52,11 @@ static int build_regex(p_regex_t *regex, const char *pattern)
 		return GIT_EINVALIDSPEC;
 	}
 
-	error = p_regcomp(regex, pattern, P_REG_EXTENDED);
+	error = git_regexp_compile(regex, pattern, 0);
 	if (!error)
 		return 0;
 
-	error = git_error_set_regex(regex, error);
-
-	p_regfree(regex);
+	git_regexp_dispose(regex);
 
 	return error;
 }
@@ -66,7 +65,7 @@ static int maybe_describe(git_object**out, git_repository *repo, const char *spe
 {
 	const char *substr;
 	int error;
-	p_regex_t regex;
+	git_regexp regex;
 
 	substr = strstr(spec, "-g");
 
@@ -76,8 +75,8 @@ static int maybe_describe(git_object**out, git_repository *repo, const char *spe
 	if (build_regex(&regex, ".+-[0-9]+-g[0-9a-fA-F]+") < 0)
 		return -1;
 
-	error = p_regexec(&regex, spec, 0, NULL, 0);
-	p_regfree(&regex);
+	error = git_regexp_match(&regex, spec);
+	git_regexp_dispose(&regex);
 
 	if (error)
 		return GIT_ENOTFOUND;
@@ -143,12 +142,11 @@ static int retrieve_previously_checked_out_branch_or_revision(git_object **out, 
 {
 	git_reference *ref = NULL;
 	git_reflog *reflog = NULL;
-	p_regex_t preg;
+	git_regexp preg;
 	int error = -1;
 	size_t i, numentries, cur;
 	const git_reflog_entry *entry;
 	const char *msg;
-	p_regmatch_t regexmatches[2];
 	git_buf buf = GIT_BUF_INIT;
 
 	cur = position;
@@ -168,12 +166,14 @@ static int retrieve_previously_checked_out_branch_or_revision(git_object **out, 
 	numentries  = git_reflog_entrycount(reflog);
 
 	for (i = 0; i < numentries; i++) {
+		git_regmatch regexmatches[2];
+
 		entry = git_reflog_entry_byindex(reflog, i);
 		msg = git_reflog_entry_message(entry);
 		if (!msg)
 			continue;
 
-		if (p_regexec(&preg, msg, 2, regexmatches, 0))
+		if (git_regexp_search(&preg, msg, 2, regexmatches) < 0)
 			continue;
 
 		cur--;
@@ -181,7 +181,8 @@ static int retrieve_previously_checked_out_branch_or_revision(git_object **out, 
 		if (cur > 0)
 			continue;
 
-		git_buf_put(&buf, msg+regexmatches[1].rm_so, regexmatches[1].rm_eo - regexmatches[1].rm_so);
+		if ((git_buf_put(&buf, msg+regexmatches[1].start, regexmatches[1].end - regexmatches[1].start)) < 0)
+			goto cleanup;
 
 		if ((error = git_reference_dwim(base_ref, repo, git_buf_cstr(&buf))) == 0)
 			goto cleanup;
@@ -199,7 +200,7 @@ static int retrieve_previously_checked_out_branch_or_revision(git_object **out, 
 cleanup:
 	git_reference_free(ref);
 	git_buf_dispose(&buf);
-	p_regfree(&preg);
+	git_regexp_dispose(&preg);
 	git_reflog_free(reflog);
 	return error;
 }
@@ -448,7 +449,7 @@ cleanup:
 	return error;
 }
 
-static int walk_and_search(git_object **out, git_revwalk *walk, p_regex_t *regex)
+static int walk_and_search(git_object **out, git_revwalk *walk, git_regexp *regex)
 {
 	int error;
 	git_oid oid;
@@ -460,7 +461,7 @@ static int walk_and_search(git_object **out, git_revwalk *walk, p_regex_t *regex
 		if ((error < 0) && (error != GIT_ENOTFOUND))
 			return -1;
 
-		if (!p_regexec(regex, git_commit_message((git_commit*)obj), 0, NULL, 0)) {
+		if (!git_regexp_match(regex, git_commit_message((git_commit*)obj))) {
 			*out = obj;
 			return 0;
 		}
@@ -476,7 +477,7 @@ static int walk_and_search(git_object **out, git_revwalk *walk, p_regex_t *regex
 
 static int handle_grep_syntax(git_object **out, git_repository *repo, const git_oid *spec_oid, const char *pattern)
 {
-	p_regex_t preg;
+	git_regexp preg;
 	git_revwalk *walk = NULL;
 	int error;
 
@@ -497,7 +498,7 @@ static int handle_grep_syntax(git_object **out, git_repository *repo, const git_
 	error = walk_and_search(out, walk, &preg);
 
 cleanup:
-	p_regfree(&preg);
+	git_regexp_dispose(&preg);
 	git_revwalk_free(walk);
 
 	return error;
diff --git a/src/userdiff.h b/src/userdiff.h
index 8bde630..c9a80d7 100644
--- a/src/userdiff.h
+++ b/src/userdiff.h
@@ -7,6 +7,8 @@
 #ifndef INCLUDE_userdiff_h__
 #define INCLUDE_userdiff_h__
 
+#include "regexp.h"
+
 /*
  * This file isolates the built in diff driver function name patterns.
  * Most of these patterns are taken from Git (with permission from the
@@ -29,7 +31,7 @@ typedef struct {
 #define PATTERNS(NAME, FN_PATS, WORD_PAT) \
 	{ NAME, FN_PATS, WORD_PAT WORD_DEFAULT, 0 }
 #define IPATTERN(NAME, FN_PATS, WORD_PAT) \
-	{ NAME, FN_PATS, WORD_PAT WORD_DEFAULT, P_REG_ICASE }
+	{ NAME, FN_PATS, WORD_PAT WORD_DEFAULT, GIT_REGEXP_ICASE }
 
 /*
  * The table of diff driver patterns