thodg/libgit2

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 38db317..f7e72d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,48 @@
+v0.27.7
+-------
+
+This is a bugfix release with the following changes or improvements:
+
+- Our continuous integration environment has switched from Travis and
+  AppVeyor to Azure Pipelines CI.
+
+- Fix adding worktrees for bare repositories.
+
+- Fix parsed patches not computing the old respectively new line
+  numbers correctly.
+
+- Fix parsing configuration variables which do not have a section.
+
+- Fix a zero-byte allocation when trying to detect file renames and
+  copies of a diff without any hunks.
+
+- Fix a zero-byte allocation when trying to resize or duplicate
+  vectors.
+
+- Fix return value when trying to unlock worktrees which aren't
+  locked.
+
+- Fix returning an unitialized error code when preparing a revision
+  walk without any pushed commits.
+
+- Fix return value of `git_remote_lookup` when lookup of
+  "remote.$remote.tagopt" fails.
+
+- Fix the revision walk always labelling commits as interesting due
+  to a mishandling of the commit date.
+
+- Fix the packbuilder inserting uninteresting blobs when adding a
+  tree containing references to such blobs.
+
+- Ignore unsupported authentication schemes in HTTP transport.
+
+- Improve performane of `git_remote_prune`.
+
+- Fix detection of whether `qsort_r` has a BSD or GNU function
+  signature.
+
+- Fix detection of iconv if it is provided by libc.
+
 v0.27.6
 -------
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7c15902..83898c5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,6 +28,7 @@ INCLUDE(CheckLibraryExists)
 INCLUDE(CheckFunctionExists)
 INCLUDE(CheckSymbolExists)
 INCLUDE(CheckStructHasMember)
+INCLUDE(CheckPrototypeDefinition) # Added in CMake 3.0
 INCLUDE(AddCFlagIfSupported)
 INCLUDE(FindPkgLibraries)
 INCLUDE(FindThreads)
@@ -224,6 +225,9 @@ ELSE ()
 	ENABLE_WARNINGS(shift-count-overflow)
 	DISABLE_WARNINGS(unused-const-variable)
 	DISABLE_WARNINGS(unused-function)
+	ENABLE_WARNINGS(format)
+	ENABLE_WARNINGS(format-security)
+	ENABLE_WARNINGS(int-conversion)
 
 	IF (APPLE) # Apple deprecated OpenSSL
 	    DISABLE_WARNINGS(deprecated-declarations)
diff --git a/cmake/Modules/CheckPrototypeDefinition.c.in b/cmake/Modules/CheckPrototypeDefinition.c.in
new file mode 100644
index 0000000..a97344a
--- /dev/null
+++ b/cmake/Modules/CheckPrototypeDefinition.c.in
@@ -0,0 +1,29 @@
+@CHECK_PROTOTYPE_DEFINITION_HEADER@
+
+static void cmakeRequireSymbol(int dummy, ...) {
+  (void) dummy;
+}
+
+static void checkSymbol(void) {
+#ifndef @CHECK_PROTOTYPE_DEFINITION_SYMBOL@
+  cmakeRequireSymbol(0, &@CHECK_PROTOTYPE_DEFINITION_SYMBOL@);
+#endif
+}
+
+@CHECK_PROTOTYPE_DEFINITION_PROTO@ {
+  return @CHECK_PROTOTYPE_DEFINITION_RETURN@;
+}
+
+#ifdef __CLASSIC_C__
+int main() {
+  int ac;
+  char*av[];
+#else
+int main(int ac, char *av[]) {
+#endif
+  checkSymbol();
+  if (ac > 1000) {
+    return *av[0];
+  }
+  return 0;
+}
diff --git a/cmake/Modules/CheckPrototypeDefinition.cmake b/cmake/Modules/CheckPrototypeDefinition.cmake
new file mode 100644
index 0000000..244b9b5
--- /dev/null
+++ b/cmake/Modules/CheckPrototypeDefinition.cmake
@@ -0,0 +1,96 @@
+# - Check if the protoype we expect is correct.
+# check_prototype_definition(FUNCTION PROTOTYPE RETURN HEADER VARIABLE)
+#  FUNCTION - The name of the function (used to check if prototype exists)
+#  PROTOTYPE- The prototype to check.
+#  RETURN - The return value of the function.
+#  HEADER - The header files required.
+#  VARIABLE - The variable to store the result.
+# Example:
+#  check_prototype_definition(getpwent_r
+#   "struct passwd *getpwent_r(struct passwd *src, char *buf, int buflen)"
+#   "NULL"
+#   "unistd.h;pwd.h"
+#   SOLARIS_GETPWENT_R)
+# The following variables may be set before calling this macro to
+# modify the way the check is run:
+#
+#  CMAKE_REQUIRED_FLAGS = string of compile command line flags
+#  CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
+#  CMAKE_REQUIRED_INCLUDES = list of include directories
+#  CMAKE_REQUIRED_LIBRARIES = list of libraries to link
+
+#=============================================================================
+# Copyright 2005-2009 Kitware, Inc.
+# Copyright 2010-2011 Andreas Schneider <asn@cryptomilk.org>
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+#
+
+get_filename_component(__check_proto_def_dir "${CMAKE_CURRENT_LIST_FILE}" PATH)
+
+function(CHECK_PROTOTYPE_DEFINITION _FUNCTION _PROTOTYPE _RETURN _HEADER _VARIABLE)
+
+  if ("${_VARIABLE}" MATCHES "^${_VARIABLE}$")
+    set(CHECK_PROTOTYPE_DEFINITION_CONTENT "/* */\n")
+
+    set(CHECK_PROTOTYPE_DEFINITION_FLAGS ${CMAKE_REQUIRED_FLAGS})
+    if (CMAKE_REQUIRED_LIBRARIES)
+      set(CHECK_PROTOTYPE_DEFINITION_LIBS
+        "-DLINK_LIBRARIES:STRING=${CMAKE_REQUIRED_LIBRARIES}")
+    else(CMAKE_REQUIRED_LIBRARIES)
+      set(CHECK_PROTOTYPE_DEFINITION_LIBS)
+    endif(CMAKE_REQUIRED_LIBRARIES)
+    if (CMAKE_REQUIRED_INCLUDES)
+      set(CMAKE_SYMBOL_EXISTS_INCLUDES
+        "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
+    else(CMAKE_REQUIRED_INCLUDES)
+      set(CMAKE_SYMBOL_EXISTS_INCLUDES)
+    endif(CMAKE_REQUIRED_INCLUDES)
+
+    foreach(_FILE ${_HEADER})
+      set(CHECK_PROTOTYPE_DEFINITION_HEADER
+        "${CHECK_PROTOTYPE_DEFINITION_HEADER}#include <${_FILE}>\n")
+    endforeach(_FILE)
+
+    set(CHECK_PROTOTYPE_DEFINITION_SYMBOL ${_FUNCTION})
+    set(CHECK_PROTOTYPE_DEFINITION_PROTO ${_PROTOTYPE})
+    set(CHECK_PROTOTYPE_DEFINITION_RETURN ${_RETURN})
+
+    configure_file("${__check_proto_def_dir}/CheckPrototypeDefinition.c.in"
+      "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckPrototypeDefinition.c" @ONLY)
+
+    file(READ ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckPrototypeDefinition.c _SOURCE)
+
+    try_compile(${_VARIABLE}
+      ${CMAKE_BINARY_DIR}
+      ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckPrototypeDefinition.c
+      COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+      CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${CHECK_PROTOTYPE_DEFINITION_FLAGS}
+      "${CHECK_PROTOTYPE_DEFINITION_LIBS}"
+      "${CMAKE_SYMBOL_EXISTS_INCLUDES}"
+      OUTPUT_VARIABLE OUTPUT)
+
+    if (${_VARIABLE})
+      set(${_VARIABLE} 1 CACHE INTERNAL "Have correct prototype for ${_FUNCTION}")
+      message(STATUS "Checking prototype ${_FUNCTION} for ${_VARIABLE} - True")
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+        "Determining if the prototype ${_FUNCTION} exists for ${_VARIABLE} passed with the following output:\n"
+        "${OUTPUT}\n\n")
+    else (${_VARIABLE})
+      message(STATUS "Checking prototype ${_FUNCTION} for ${_VARIABLE} - False")
+      set(${_VARIABLE} 0 CACHE INTERNAL "Have correct prototype for ${_FUNCTION}")
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+        "Determining if the prototype ${_FUNCTION} exists for ${_VARIABLE} failed with the following output:\n"
+        "${OUTPUT}\n\n${_SOURCE}\n\n")
+    endif (${_VARIABLE})
+  endif("${_VARIABLE}" MATCHES "^${_VARIABLE}$")
+
+endfunction(CHECK_PROTOTYPE_DEFINITION)
diff --git a/cmake/Modules/FindIconv.cmake b/cmake/Modules/FindIconv.cmake
index 95414bd..3c66cda 100644
--- a/cmake/Modules/FindIconv.cmake
+++ b/cmake/Modules/FindIconv.cmake
@@ -12,14 +12,19 @@ IF(ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)
 ENDIF()
 
 FIND_PATH(ICONV_INCLUDE_DIR iconv.h)
+CHECK_FUNCTION_EXISTS(iconv_open libc_has_iconv)
 FIND_LIBRARY(iconv_lib NAMES iconv libiconv libiconv-2 c)
 
-IF(ICONV_INCLUDE_DIR AND iconv_lib)
-	 SET(ICONV_FOUND TRUE)
-ENDIF()
-
-IF(ICONV_FOUND)
-	# split iconv into -L and -l linker options, so we can set them for pkg-config
+IF(ICONV_INCLUDE_DIR AND libc_has_iconv)
+	SET(ICONV_FOUND TRUE)
+	SET(ICONV_LIBRARIES "")
+	IF(NOT ICONV_FIND_QUIETLY)
+		MESSAGE(STATUS "Found Iconv: provided by libc")
+	ENDIF(NOT ICONV_FIND_QUIETLY)
+ELSEIF(ICONV_INCLUDE_DIR AND iconv_lib)
+	SET(ICONV_FOUND TRUE)
+	# split iconv into -L and -l linker options, so we can
+	# set them for pkg-config
 	GET_FILENAME_COMPONENT(iconv_path ${iconv_lib} PATH)
 	GET_FILENAME_COMPONENT(iconv_name ${iconv_lib} NAME_WE)
 	STRING(REGEX REPLACE "^lib" "" iconv_name ${iconv_name})
diff --git a/include/git2/version.h b/include/git2/version.h
index 8dd6a5e..964e4a5 100644
--- a/include/git2/version.h
+++ b/include/git2/version.h
@@ -7,10 +7,10 @@
 #ifndef INCLUDE_git_version_h__
 #define INCLUDE_git_version_h__
 
-#define LIBGIT2_VERSION "0.27.6"
+#define LIBGIT2_VERSION "0.27.7"
 #define LIBGIT2_VER_MAJOR 0
 #define LIBGIT2_VER_MINOR 27
-#define LIBGIT2_VER_REVISION 6
+#define LIBGIT2_VER_REVISION 7
 #define LIBGIT2_VER_PATCH 0
 
 #define LIBGIT2_SOVERSION 27
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4cfb2d3..2080933 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -57,10 +57,19 @@ IF (HAVE_FUTIMENS)
 	SET(GIT_USE_FUTIMENS 1)
 ENDIF ()
 
-CHECK_FUNCTION_EXISTS(qsort_r HAVE_QSORT_R)
-IF (HAVE_QSORT_R)
-	ADD_DEFINITIONS(-DHAVE_QSORT_R)
-ENDIF ()
+CHECK_PROTOTYPE_DEFINITION(qsort_r
+	"void qsort_r(void *base, size_t nmemb, size_t size, void *thunk, int (*compar)(void *, const void *, const void *))"
+	"" "stdlib.h" HAVE_QSORT_R_BSD)
+IF (HAVE_QSORT_R_BSD)
+	ADD_DEFINITIONS(-DHAVE_QSORT_R_BSD)
+ENDIF()
+
+CHECK_PROTOTYPE_DEFINITION(qsort_r
+	"void qsort_r(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *, void *), void *arg)"
+	"" "stdlib.h" HAVE_QSORT_R_GNU)
+IF (HAVE_QSORT_R_GNU)
+	ADD_DEFINITIONS(-DHAVE_QSORT_R_GNU)
+ENDIF()
 
 CHECK_FUNCTION_EXISTS(qsort_s HAVE_QSORT_S)
 IF (HAVE_QSORT_S)
diff --git a/src/config_file.c b/src/config_file.c
index 0f4eb0e..0c05fb5 100644
--- a/src/config_file.c
+++ b/src/config_file.c
@@ -1075,8 +1075,16 @@ static int read_on_variable(
 	GIT_UNUSED(line);
 	GIT_UNUSED(line_len);
 
+	if (current_section) {
+		/* TODO: Once warnings lang, we should likely warn
+		 * here. Git appears to warn in most cases if it sees
+		 * un-namespaced config options.
+		 */
+		git_buf_puts(&buf, current_section);
+		git_buf_putc(&buf, '.');
+	}
 	git__strtolower(var_name);
-	git_buf_printf(&buf, "%s.%s", current_section, var_name);
+	git_buf_puts(&buf, var_name);
 	git__free(var_name);
 
 	if (git_buf_oom(&buf)) {
diff --git a/src/diff_tform.c b/src/diff_tform.c
index bc664dd..a9706e0 100644
--- a/src/diff_tform.c
+++ b/src/diff_tform.c
@@ -822,7 +822,7 @@ int git_diff_find_similar(
 	num_deltas = diff->deltas.length;
 
 	/* TODO: maybe abort if deltas.length > rename_limit ??? */
-	if (!git__is_uint32(num_deltas))
+	if (!num_deltas || !git__is_uint32(num_deltas))
 		goto cleanup;
 
 	/* No flags set; nothing to do */
diff --git a/src/index.c b/src/index.c
index 7a8bb2c..2b47e4d 100644
--- a/src/index.c
+++ b/src/index.c
@@ -1774,7 +1774,8 @@ int git_index_conflict_add(git_index *index,
 		if (entries[i] && !valid_filemode(entries[i]->mode)) {
 			giterr_set(GITERR_INDEX, "invalid filemode for stage %d entry",
 				i + 1);
-			return -1;
+			ret = -1;
+			goto on_error;
 		}
 	}
 
@@ -3509,7 +3510,7 @@ int git_index_snapshot_new(git_vector *snap, git_index *index)
 	error = git_vector_dup(snap, &index->entries, index->entries._cmp);
 
 	if (error < 0)
-		git_index_free(index);
+		git_index_snapshot_release(snap, index);
 
 	return error;
 }
diff --git a/src/pack-objects.c b/src/pack-objects.c
index e924514..355b9e1 100644
--- a/src/pack-objects.c
+++ b/src/pack-objects.c
@@ -1666,7 +1666,7 @@ int insert_tree(git_packbuilder *pb, git_tree *tree)
 
 			break;
 		case GIT_OBJ_BLOB:
-			if ((error = retrieve_object(&obj, pb, git_tree_id(tree))) < 0)
+			if ((error = retrieve_object(&obj, pb, entry_id)) < 0)
 				return error;
 			if (obj->uninteresting)
 				continue;
diff --git a/src/parse.c b/src/parse.c
index 6b8902c..b04fda3 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -8,12 +8,14 @@
 
 int git_parse_ctx_init(git_parse_ctx *ctx, const char *content, size_t content_len)
 {
-	if (content_len)
+	if (content && content_len) {
 		ctx->content = content;
-	else
-		ctx->content = NULL;
+		ctx->content_len = content_len;
+	} else {
+		ctx->content = "";
+		ctx->content_len = 0;
+	}
 
-	ctx->content_len = content_len;
 	ctx->remain = ctx->content;
 	ctx->remain_len = ctx->content_len;
 	ctx->line = ctx->remain;
@@ -26,6 +28,7 @@ int git_parse_ctx_init(git_parse_ctx *ctx, const char *content, size_t content_l
 void git_parse_ctx_clear(git_parse_ctx *ctx)
 {
 	memset(ctx, 0, sizeof(*ctx));
+	ctx->content = "";
 }
 
 void git_parse_advance_line(git_parse_ctx *ctx)
diff --git a/src/patch_parse.c b/src/patch_parse.c
index acdd45e..e02c87c 100644
--- a/src/patch_parse.c
+++ b/src/patch_parse.c
@@ -563,6 +563,8 @@ static int parse_hunk_body(
 		char c;
 		int origin;
 		int prefix = 1;
+		int old_lineno = hunk->hunk.old_start + (hunk->hunk.old_lines - oldlines);
+		int new_lineno = hunk->hunk.new_start + (hunk->hunk.new_lines - newlines);
 
 		if (ctx->parse_ctx.line_len == 0 || ctx->parse_ctx.line[ctx->parse_ctx.line_len - 1] != '\n') {
 			error = git_parse_err("invalid patch instruction at line %"PRIuZ,
@@ -586,11 +588,13 @@ static int parse_hunk_body(
 		case '-':
 			origin = GIT_DIFF_LINE_DELETION;
 			oldlines--;
+			new_lineno = -1;
 			break;
 
 		case '+':
 			origin = GIT_DIFF_LINE_ADDITION;
 			newlines--;
+			old_lineno = -1;
 			break;
 
 		default:
@@ -607,6 +611,9 @@ static int parse_hunk_body(
 		line->content_len = ctx->parse_ctx.line_len - prefix;
 		line->content_offset = ctx->parse_ctx.content_len - ctx->parse_ctx.remain_len;
 		line->origin = origin;
+		line->num_lines = 1;
+		line->old_lineno = old_lineno;
+		line->new_lineno = new_lineno;
 
 		hunk->line_count++;
 	}
diff --git a/src/remote.c b/src/remote.c
index d8a6b99..2078dd3 100644
--- a/src/remote.c
+++ b/src/remote.c
@@ -428,7 +428,7 @@ static int get_optional_config(
 
 int git_remote_lookup(git_remote **out, git_repository *repo, const char *name)
 {
-	git_remote *remote;
+	git_remote *remote = NULL;
 	git_buf buf = GIT_BUF_INIT;
 	const char *val;
 	int error = 0;
@@ -510,7 +510,7 @@ int git_remote_lookup(git_remote **out, git_repository *repo, const char *name)
 	if ((error = get_optional_config(NULL, config, &buf, refspec_cb, &data)) < 0)
 		goto cleanup;
 
-	if (download_tags_value(remote, config) < 0)
+	if ((error = download_tags_value(remote, config)) < 0)
 		goto cleanup;
 
 	if ((error = lookup_remote_prune_config(remote, config, name)) < 0)
@@ -1234,7 +1234,7 @@ int git_remote_prune(git_remote *remote, const git_remote_callbacks *callbacks)
 				goto cleanup;
 
 			key.name = (char *) git_buf_cstr(&buf);
-			error = git_vector_search(&pos, &remote_refs, &key);
+			error = git_vector_bsearch(&pos, &remote_refs, &key);
 			git_buf_free(&buf);
 
 			if (error < 0 && error != GIT_ENOTFOUND)
diff --git a/src/repository.c b/src/repository.c
index 90b778e..3c89879 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -268,11 +268,15 @@ static int load_config_data(git_repository *repo, const git_config *config)
 {
 	int is_bare;
 
+	int err = git_config_get_bool(&is_bare, config, "core.bare");
+	if (err < 0 && err != GIT_ENOTFOUND)
+		return err;
+
 	/* Try to figure out if it's bare, default to non-bare if it's not set */
-	if (git_config_get_bool(&is_bare, config, "core.bare") < 0)
-		repo->is_bare = 0;
+	if (err != GIT_ENOTFOUND)
+		repo->is_bare = is_bare && !repo->is_worktree;
 	else
-		repo->is_bare = is_bare;
+		repo->is_bare = 0;
 
 	return 0;
 }
diff --git a/src/revwalk.c b/src/revwalk.c
index eb228a5..f11dc06 100644
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -384,10 +384,16 @@ static int still_interesting(git_commit_list *list, int64_t time, int slop)
 	if (!list)
 		return 0;
 
+	/*
+	 * If the destination list has commits with an earlier date than our
+	 * source, we want to reset the slop counter as we're not done.
+	 */
+	if (time <= list->item->time)
+		return SLOP;
+
 	for (; list; list = list->next) {
 		/*
-		 * If the destination list has commits with an earlier date than
-		 * our source or if it still contains interesting commits we
+		 * If the destination list still contains interesting commits we
 		 * want to continue looking.
 		 */
 		if (!list->item->uninteresting || list->item->time > time)
@@ -401,7 +407,7 @@ static int still_interesting(git_commit_list *list, int64_t time, int slop)
 static int limit_list(git_commit_list **out, git_revwalk *walk, git_commit_list *commits)
 {
 	int error, slop = SLOP;
-	int64_t time = ~0ll;
+	int64_t time = INT64_MAX;
 	git_commit_list *list = commits;
 	git_commit_list *newlist = NULL;
 	git_commit_list **p = &newlist;
@@ -522,7 +528,7 @@ cleanup:
 
 static int prepare_walk(git_revwalk *walk)
 {
-	int error;
+	int error = 0;
 	git_commit_list *list, *commits = NULL;
 	git_commit_list_node *next;
 
diff --git a/src/transports/http.c b/src/transports/http.c
index e051c8a..22b8bb8 100644
--- a/src/transports/http.c
+++ b/src/transports/http.c
@@ -188,6 +188,9 @@ static int apply_credentials(git_buf *buf, http_subtransport *t)
 	if (auth_context_match(&context, t, credtype_match, &cred->credtype) < 0)
 		return -1;
 
+	if (!context)
+		return 0;
+
 	return context->next_token(buf, context, cred);
 }
 
diff --git a/src/transports/winhttp.c b/src/transports/winhttp.c
index 4a1eb04..c3c18a8 100644
--- a/src/transports/winhttp.c
+++ b/src/transports/winhttp.c
@@ -846,23 +846,27 @@ on_error:
 
 static int do_send_request(winhttp_stream *s, size_t len, int ignore_length)
 {
-	if (ignore_length) {
-		if (!WinHttpSendRequest(s->request,
-			WINHTTP_NO_ADDITIONAL_HEADERS, 0,
-			WINHTTP_NO_REQUEST_DATA, 0,
-			WINHTTP_IGNORE_REQUEST_TOTAL_LENGTH, 0)) {
-			return -1;
-		}
-	} else {
-		if (!WinHttpSendRequest(s->request,
-			WINHTTP_NO_ADDITIONAL_HEADERS, 0,
-			WINHTTP_NO_REQUEST_DATA, 0,
-			len, 0)) {
-			return -1;
+	int attempts;
+	bool success;
+
+	for (attempts = 0; attempts < 5; attempts++) {
+		if (ignore_length) {
+			success = WinHttpSendRequest(s->request,
+				WINHTTP_NO_ADDITIONAL_HEADERS, 0,
+				WINHTTP_NO_REQUEST_DATA, 0,
+				WINHTTP_IGNORE_REQUEST_TOTAL_LENGTH, 0);
+		} else {
+			success = WinHttpSendRequest(s->request,
+				WINHTTP_NO_ADDITIONAL_HEADERS, 0,
+				WINHTTP_NO_REQUEST_DATA, 0,
+				len, 0);
 		}
+
+		if (success || GetLastError() != SEC_E_BUFFER_TOO_SMALL)
+			break;
 	}
 
-	return 0;
+	return success ? 0 : -1;
 }
 
 static int send_request(winhttp_stream *s, size_t len, int ignore_length)
diff --git a/src/tree.c b/src/tree.c
index 1262297..a014ce8 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -490,15 +490,16 @@ static int append_entry(
 	git_treebuilder *bld,
 	const char *filename,
 	const git_oid *id,
-	git_filemode_t filemode)
+	git_filemode_t filemode,
+	bool validate)
 {
 	git_tree_entry *entry;
 	int error = 0;
 
-	if (!valid_entry_name(bld->repo, filename))
+	if (validate && !valid_entry_name(bld->repo, filename))
 		return tree_error("failed to insert entry: invalid name for a tree entry", filename);
 
-	if (git_oid_iszero(id))
+	if (validate && git_oid_iszero(id))
 		return tree_error("failed to insert entry: invalid null OID for a tree entry", filename);
 
 	entry = alloc_entry(filename, strlen(filename), id);
@@ -596,12 +597,12 @@ static int write_tree(
 				last_comp = subdir;
 			}
 
-			error = append_entry(bld, last_comp, &sub_oid, S_IFDIR);
+			error = append_entry(bld, last_comp, &sub_oid, S_IFDIR, true);
 			git__free(subdir);
 			if (error < 0)
 				goto on_error;
 		} else {
-			error = append_entry(bld, filename, &entry->id, entry->mode);
+			error = append_entry(bld, filename, &entry->id, entry->mode, true);
 			if (error < 0)
 				goto on_error;
 		}
@@ -699,7 +700,8 @@ int git_treebuilder_new(
 			if (append_entry(
 				bld, entry_src->filename,
 				entry_src->oid,
-				entry_src->attr) < 0)
+				entry_src->attr,
+				false) < 0)
 				goto on_error;
 		}
 	}
diff --git a/src/util.c b/src/util.c
index 48cac85..9119218 100644
--- a/src/util.c
+++ b/src/util.c
@@ -690,7 +690,7 @@ size_t git__unescape(char *str)
 	return (pos - str);
 }
 
-#if defined(HAVE_QSORT_S) || (defined(HAVE_QSORT_R) && defined(BSD))
+#if defined(HAVE_QSORT_S) || defined(HAVE_QSORT_R_BSD)
 typedef struct {
 	git__sort_r_cmp cmp;
 	void *payload;
@@ -707,10 +707,10 @@ static int GIT_STDLIB_CALL git__qsort_r_glue_cmp(
 void git__qsort_r(
 	void *els, size_t nel, size_t elsize, git__sort_r_cmp cmp, void *payload)
 {
-#if defined(HAVE_QSORT_R) && defined(BSD)
+#if defined(HAVE_QSORT_R_BSD)
 	git__qsort_r_glue glue = { cmp, payload };
 	qsort_r(els, nel, elsize, &glue, git__qsort_r_glue_cmp);
-#elif defined(HAVE_QSORT_R) && defined(__GLIBC__)
+#elif defined(HAVE_QSORT_R_GNU)
 	qsort_r(els, nel, elsize, cmp, payload);
 #elif defined(HAVE_QSORT_S)
 	git__qsort_r_glue glue = { cmp, payload };
diff --git a/src/vector.c b/src/vector.c
index b12fa94..98aa7bb 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -32,6 +32,9 @@ GIT_INLINE(int) resize_vector(git_vector *v, size_t new_size)
 {
 	void *new_contents;
 
+	if (new_size == 0)
+		return 0;
+
 	new_contents = git__reallocarray(v->contents, new_size, sizeof(void *));
 	GITERR_CHECK_ALLOC(new_contents);
 
@@ -50,22 +53,24 @@ int git_vector_size_hint(git_vector *v, size_t size_hint)
 
 int git_vector_dup(git_vector *v, const git_vector *src, git_vector_cmp cmp)
 {
-	size_t bytes;
-
 	assert(v && src);
 
-	GITERR_CHECK_ALLOC_MULTIPLY(&bytes, src->length, sizeof(void *));
-
-	v->_alloc_size = src->length;
+	v->_alloc_size = 0;
+	v->contents = NULL;
 	v->_cmp = cmp ? cmp : src->_cmp;
 	v->length = src->length;
 	v->flags  = src->flags;
 	if (cmp != src->_cmp)
 		git_vector_set_sorted(v, 0);
-	v->contents = git__malloc(bytes);
-	GITERR_CHECK_ALLOC(v->contents);
 
-	memcpy(v->contents, src->contents, bytes);
+	if (src->length) {
+		size_t bytes;
+		GITERR_CHECK_ALLOC_MULTIPLY(&bytes, src->length, sizeof(void *));
+		v->contents = git__malloc(bytes);
+		GITERR_CHECK_ALLOC(v->contents);
+		v->_alloc_size = src->length;
+		memcpy(v->contents, src->contents, bytes);
+	}
 
 	return 0;
 }
diff --git a/src/worktree.c b/src/worktree.c
index 9152766..4acf61b 100644
--- a/src/worktree.c
+++ b/src/worktree.c
@@ -139,7 +139,7 @@ static int open_worktree_dir(git_worktree **out, const char *parent, const char 
 	if ((wt->name = git__strdup(name)) == NULL
 	    || (wt->commondir_path = git_worktree__read_link(dir, "commondir")) == NULL
 	    || (wt->gitlink_path = git_worktree__read_link(dir, "gitdir")) == NULL
-	    || (wt->parent_path = git__strdup(parent)) == NULL) {
+	    || (parent && (wt->parent_path = git__strdup(parent)) == NULL)) {
 		error = -1;
 		goto out;
 	}
@@ -417,7 +417,7 @@ int git_worktree_unlock(git_worktree *wt)
 	assert(wt);
 
 	if (!git_worktree_is_locked(NULL, wt))
-		return 0;
+		return 1;
 
 	if (git_buf_joinpath(&path, wt->gitdir_path, "locked") < 0)
 		return -1;
diff --git a/tests/config/read.c b/tests/config/read.c
index a34455a..6465671 100644
--- a/tests/config/read.c
+++ b/tests/config/read.c
@@ -748,3 +748,36 @@ void test_config_read__bom(void)
 	git_config_free(cfg);
 	git_buf_free(&buf);
 }
+
+static int read_nosection_cb(const git_config_entry *entry, void *payload) {
+	int *seen = (int*)payload;
+	if (strcmp(entry->name, "key") == 0) {
+		(*seen)++;
+	}
+	return 0;
+}
+
+/* This would ideally issue a warning, if we had a way to do so. */
+void test_config_read__nosection(void)
+{
+	git_config *cfg;
+	git_buf buf = GIT_BUF_INIT;
+	int seen = 0;
+
+	cl_git_pass(git_config_open_ondisk(&cfg, cl_fixture("config/config-nosection")));
+
+	/*
+	 * Given a key with no section, we do not allow reading it,
+	 * but we do include it in an iteration over the config
+	 * store. This appears to match how git's own APIs (and
+	 * git-config(1)) behave.
+	 */
+
+	cl_git_fail_with(git_config_get_string_buf(&buf, cfg, "key"), GIT_EINVALIDSPEC);
+
+	cl_git_pass(git_config_foreach(cfg, read_nosection_cb, &seen));
+	cl_assert_equal_i(seen, 1);
+
+	git_buf_free(&buf);
+	git_config_free(cfg);
+}
diff --git a/tests/core/vector.c b/tests/core/vector.c
index c2e5d3f..9145240 100644
--- a/tests/core/vector.c
+++ b/tests/core/vector.c
@@ -407,3 +407,22 @@ void test_core_vector__reverse(void)
 
 	git_vector_free(&v);
 }
+
+void test_core_vector__dup_empty_vector(void)
+{
+	git_vector v = GIT_VECTOR_INIT;
+	git_vector dup = GIT_VECTOR_INIT;
+	int dummy;
+
+	cl_assert_equal_i(0, v.length);
+
+	cl_git_pass(git_vector_dup(&dup, &v, v._cmp));
+	cl_assert_equal_i(0, dup._alloc_size);
+	cl_assert_equal_i(0, dup.length);
+
+	cl_git_pass(git_vector_insert(&dup, &dummy));
+	cl_assert_equal_i(8, dup._alloc_size);
+	cl_assert_equal_i(1, dup.length);
+
+	git_vector_free(&dup);
+}
diff --git a/tests/diff/parse.c b/tests/diff/parse.c
index dc2ceef..74816f5 100644
--- a/tests/diff/parse.c
+++ b/tests/diff/parse.c
@@ -288,3 +288,74 @@ void test_diff_parse__patch_roundtrip_succeeds(void)
 	git_buf_free(&patchbuf);
 	git_buf_free(&diffbuf);
 }
+
+#define cl_assert_equal_i_src(i1,i2,file,line) clar__assert_equal(file,line,#i1 " != " #i2, 1, "%d", (int)(i1), (int)(i2))
+
+static void cl_git_assert_lineinfo_(int old_lineno, int new_lineno, int num_lines, git_patch *patch, size_t hunk_idx, size_t line_idx, const char *file, int lineno)
+{
+	const git_diff_line *line;
+
+	cl_git_expect(git_patch_get_line_in_hunk(&line, patch, hunk_idx, line_idx), 0, file, lineno);
+	cl_assert_equal_i_src(old_lineno, line->old_lineno, file, lineno);
+	cl_assert_equal_i_src(new_lineno, line->new_lineno, file, lineno);
+	cl_assert_equal_i_src(num_lines, line->num_lines, file, lineno);
+}
+
+#define cl_git_assert_lineinfo(old, new, num, p, h, l) \
+	cl_git_assert_lineinfo_(old,new,num,p,h,l,__FILE__,__LINE__)
+
+
+void test_diff_parse__issue4672(void)
+{
+	const char *text = "diff --git a/a b/a\n"
+	"index 7f129fd..af431f2 100644\n"
+	"--- a/a\n"
+	"+++ b/a\n"
+	"@@ -3 +3 @@\n"
+	"-a contents 2\n"
+	"+a contents\n";
+
+	git_diff *diff;
+	git_patch *patch;
+	const git_diff_hunk *hunk;
+	size_t n, l = 0;
+
+	cl_git_pass(git_diff_from_buffer(&diff, text, strlen(text)));
+	cl_git_pass(git_patch_from_diff(&patch, diff, 0));
+	cl_git_pass(git_patch_get_hunk(&hunk, &n, patch, 0));
+
+	cl_git_assert_lineinfo(3, -1, 1, patch, 0, l++);
+	cl_git_assert_lineinfo(-1, 3, 1, patch, 0, l++);
+
+	cl_assert_equal_i(n, l);
+
+	git_patch_free(patch);
+	git_diff_free(diff);
+}
+
+void test_diff_parse__lineinfo(void)
+{
+	const char *text = PATCH_ORIGINAL_TO_CHANGE_MIDDLE;
+	git_diff *diff;
+	git_patch *patch;
+	const git_diff_hunk *hunk;
+	size_t n, l = 0;
+
+	cl_git_pass(git_diff_from_buffer(&diff, text, strlen(text)));
+	cl_git_pass(git_patch_from_diff(&patch, diff, 0));
+	cl_git_pass(git_patch_get_hunk(&hunk, &n, patch, 0));
+
+	cl_git_assert_lineinfo(3, 3, 1, patch, 0, l++);
+	cl_git_assert_lineinfo(4, 4, 1, patch, 0, l++);
+	cl_git_assert_lineinfo(5, 5, 1, patch, 0, l++);
+	cl_git_assert_lineinfo(6, -1, 1, patch, 0, l++);
+	cl_git_assert_lineinfo(-1, 6, 1, patch, 0, l++);
+	cl_git_assert_lineinfo(7, 7, 1, patch, 0, l++);
+	cl_git_assert_lineinfo(8, 8, 1, patch, 0, l++);
+	cl_git_assert_lineinfo(9, 9, 1, patch, 0, l++);
+
+	cl_assert_equal_i(n, l);
+
+	git_patch_free(patch);
+	git_diff_free(diff);
+}
diff --git a/tests/object/tree/update.c b/tests/object/tree/update.c
index b76e861..41b50f3 100644
--- a/tests/object/tree/update.c
+++ b/tests/object/tree/update.c
@@ -284,3 +284,19 @@ void test_object_tree_update__add_conflict2(void)
 
 	cl_git_fail(git_tree_create_updated(&tree_updater_id, g_repo, NULL, 2, updates));
 }
+
+void test_object_tree_update__remove_invalid_submodule(void)
+{
+	git_tree *baseline;
+	git_oid updated_tree_id, baseline_id;
+	git_tree_update updates[] = {
+		{GIT_TREE_UPDATE_REMOVE, {{0}}, GIT_FILEMODE_BLOB, "submodule"},
+	};
+
+	/* This tree contains a submodule with an all-zero commit for a submodule named 'submodule' */
+	cl_git_pass(git_oid_fromstr(&baseline_id, "396c7f1adb7925f51ba13a75f48252f44c5a14a2"));
+	cl_git_pass(git_tree_lookup(&baseline, g_repo, &baseline_id));
+	cl_git_pass(git_tree_create_updated(&updated_tree_id, g_repo, baseline, 1, updates));
+
+	git_tree_free(baseline);
+}
diff --git a/tests/resources/config/config-nosection b/tests/resources/config/config-nosection
new file mode 100644
index 0000000..dd2ee08
--- /dev/null
+++ b/tests/resources/config/config-nosection
@@ -0,0 +1 @@
+key = value
diff --git a/tests/resources/testrepo2/.gitted/objects/39/6c7f1adb7925f51ba13a75f48252f44c5a14a2 b/tests/resources/testrepo2/.gitted/objects/39/6c7f1adb7925f51ba13a75f48252f44c5a14a2
new file mode 100644
index 0000000..667704b
Binary files /dev/null and b/tests/resources/testrepo2/.gitted/objects/39/6c7f1adb7925f51ba13a75f48252f44c5a14a2 differ
diff --git a/tests/worktree/worktree.c b/tests/worktree/worktree.c
index 4ac3b8b..9026a7f 100644
--- a/tests/worktree/worktree.c
+++ b/tests/worktree/worktree.c
@@ -228,6 +228,26 @@ void test_worktree_worktree__init(void)
 	git_repository_free(repo);
 }
 
+void test_worktree_worktree__add_from_bare(void)
+{
+	git_worktree *wt;
+	git_repository *repo, *wtrepo;
+
+	repo = cl_git_sandbox_init("short_tag.git");
+
+	cl_assert_equal_i(1, git_repository_is_bare(repo));
+	cl_assert_equal_i(0, git_repository_is_worktree(repo));
+
+	cl_git_pass(git_worktree_add(&wt, repo, "worktree-frombare", "worktree-frombare", NULL));
+	cl_git_pass(git_repository_open(&wtrepo, "worktree-frombare"));
+	cl_assert_equal_i(0, git_repository_is_bare(wtrepo));
+	cl_assert_equal_i(1, git_repository_is_worktree(wtrepo));
+
+	git_worktree_free(wt);
+	git_repository_free(repo);
+	git_repository_free(wtrepo);
+}
+
 void test_worktree_worktree__add_locked(void)
 {
 	git_worktree *wt;
@@ -435,7 +455,7 @@ void test_worktree_worktree__unlock_unlocked_worktree(void)
 
 	cl_git_pass(git_worktree_lookup(&wt, fixture.repo, "testrepo-worktree"));
 	cl_assert(!git_worktree_is_locked(NULL, wt));
-	cl_assert(git_worktree_unlock(wt) == 0);
+	cl_assert_equal_i(1, git_worktree_unlock(wt));
 	cl_assert(!wt->locked);
 
 	git_worktree_free(wt);
@@ -448,7 +468,7 @@ void test_worktree_worktree__unlock_locked_worktree(void)
 	cl_git_pass(git_worktree_lookup(&wt, fixture.repo, "testrepo-worktree"));
 	cl_git_pass(git_worktree_lock(wt, NULL));
 	cl_assert(git_worktree_is_locked(NULL, wt));
-	cl_git_pass(git_worktree_unlock(wt));
+	cl_assert_equal_i(0, git_worktree_unlock(wt));
 	cl_assert(!wt->locked);
 
 	git_worktree_free(wt);