str: introduce `git_str` for internal, `git_buf` is externalethomson/gitstr

libgit2 has two distinct requirements that were previously solved by
`git_buf`.  We require:

1. A general purpose string class that provides a number of utility APIs
   for manipulating data (eg, concatenating, truncating, etc).
2. A structure that we can use to return strings to callers that they
   can take ownership of.

By using a single class (`git_buf`) for both of these purposes, we have
confused the API to the point that refactorings are difficult and
reasoning about correctness is also difficult.

Move the utility class `git_buf` to be called `git_str`: this represents
its general purpose, as an internal string buffer class.  The name also
is an homage to Junio Hamano ("gitstr").

The public API remains `git_buf`, and has a much smaller footprint.  It
is generally only used as an "out" param with strict requirements that
follow the documentation.  (Exceptions exist for some legacy APIs to
avoid breaking callers unnecessarily.)

Utility functions exist to convert a user-specified `git_buf` to a
`git_str` so that we can call internal functions, then converting it
back again.

1 files changed, 24 insertions, 25 deletions

diff --git a/tests/config/write.c b/tests/config/write.c
index 78ed7f15b..4ee83833f 100644
--- a/tests/config/write.c
+++ b/tests/config/write.c
@@ -1,5 +1,4 @@
 #include "clar_libgit2.h"
-#include "buffer.h"
 #include "futils.h"
 #include "git2/sys/config.h"
 #include "config.h"
@@ -290,7 +289,7 @@ void test_config_write__write_subsection(void)
 
 	cl_git_pass(git_config_open_ondisk(&cfg, "config9"));
 	cl_git_pass(git_config_get_string_buf(&buf, cfg, "my.own.var"));
-	cl_assert_equal_s("works", git_buf_cstr(&buf));
+	cl_assert_equal_s("works", buf.ptr);
 
 	git_buf_dispose(&buf);
 	git_config_free(cfg);
@@ -313,27 +312,27 @@ void test_config_write__value_containing_quotes(void)
 	cl_git_pass(git_config_open_ondisk(&cfg, "config9"));
 	cl_git_pass(git_config_set_string(cfg, "core.somevar", "this \"has\" quotes"));
 	cl_git_pass(git_config_get_string_buf(&buf, cfg, "core.somevar"));
-	cl_assert_equal_s("this \"has\" quotes", git_buf_cstr(&buf));
-	git_buf_clear(&buf);
+	cl_assert_equal_s("this \"has\" quotes", buf.ptr);
+	git_buf_dispose(&buf);
 	git_config_free(cfg);
 
 	cl_git_pass(git_config_open_ondisk(&cfg, "config9"));
 	cl_git_pass(git_config_get_string_buf(&buf, cfg, "core.somevar"));
-	cl_assert_equal_s("this \"has\" quotes", git_buf_cstr(&buf));
-	git_buf_clear(&buf);
+	cl_assert_equal_s("this \"has\" quotes", buf.ptr);
+	git_buf_dispose(&buf);
 	git_config_free(cfg);
 
 	/* The code path for values that already exist is different, check that one as well */
 	cl_git_pass(git_config_open_ondisk(&cfg, "config9"));
 	cl_git_pass(git_config_set_string(cfg, "core.somevar", "this also \"has\" quotes"));
 	cl_git_pass(git_config_get_string_buf(&buf, cfg, "core.somevar"));
-	cl_assert_equal_s("this also \"has\" quotes", git_buf_cstr(&buf));
-	git_buf_clear(&buf);
+	cl_assert_equal_s("this also \"has\" quotes", buf.ptr);
+	git_buf_dispose(&buf);
 	git_config_free(cfg);
 
 	cl_git_pass(git_config_open_ondisk(&cfg, "config9"));
 	cl_git_pass(git_config_get_string_buf(&buf, cfg, "core.somevar"));
-	cl_assert_equal_s("this also \"has\" quotes", git_buf_cstr(&buf));
+	cl_assert_equal_s("this also \"has\" quotes", buf.ptr);
 	git_buf_dispose(&buf);
 	git_config_free(cfg);
 }
@@ -346,13 +345,13 @@ void test_config_write__escape_value(void)
 	cl_git_pass(git_config_open_ondisk(&cfg, "config9"));
 	cl_git_pass(git_config_set_string(cfg, "core.somevar", "this \"has\" quotes and \t"));
 	cl_git_pass(git_config_get_string_buf(&buf, cfg, "core.somevar"));
-	cl_assert_equal_s("this \"has\" quotes and \t", git_buf_cstr(&buf));
-	git_buf_clear(&buf);
+	cl_assert_equal_s("this \"has\" quotes and \t", buf.ptr);
+	git_buf_dispose(&buf);
 	git_config_free(cfg);
 
 	cl_git_pass(git_config_open_ondisk(&cfg, "config9"));
 	cl_git_pass(git_config_get_string_buf(&buf, cfg, "core.somevar"));
-	cl_assert_equal_s("this \"has\" quotes and \t", git_buf_cstr(&buf));
+	cl_assert_equal_s("this \"has\" quotes and \t", buf.ptr);
 	git_buf_dispose(&buf);
 	git_config_free(cfg);
 }
@@ -390,7 +389,7 @@ void test_config_write__add_value_at_specific_level(void)
 	cl_git_pass(git_config_get_bool(&i, cfg, "core.boolglobal"));
 	cl_assert_equal_b(true, i);
 	cl_git_pass(git_config_get_string_buf(&buf, cfg, "core.stringglobal"));
-	cl_assert_equal_s("I'm a global config value!", git_buf_cstr(&buf));
+	cl_assert_equal_s("I'm a global config value!", buf.ptr);
 
 	git_buf_dispose(&buf);
 	git_config_free(cfg);
@@ -553,7 +552,7 @@ void test_config_write__preserves_whitespace_and_comments(void)
 	const char *file_name  = "config-duplicate-header";
 	const char *n;
 	git_config *cfg;
-	git_buf newfile = GIT_BUF_INIT;
+	git_str newfile = GIT_STR_INIT;
 
 	/* This config can occur after removing and re-adding the origin remote */
 	const char *file_content = SECTION_FOO_WITH_COMMENT SECTION_BAR;
@@ -580,7 +579,7 @@ void test_config_write__preserves_whitespace_and_comments(void)
 
 	cl_assert_equal_s("[newsection]\n\tnewname = new_value\n", n);
 
-	git_buf_dispose(&newfile);
+	git_str_dispose(&newfile);
 	git_config_free(cfg);
 }
 
@@ -588,7 +587,7 @@ void test_config_write__preserves_entry_with_name_only(void)
 {
 	const char *file_name  = "config-empty-value";
 	git_config *cfg;
-	git_buf newfile = GIT_BUF_INIT;
+	git_str newfile = GIT_STR_INIT;
 
 	/* Write the test config and make sure the expected entry exists */
 	cl_git_mkfile(file_name, "[section \"foo\"]\n\tname\n");
@@ -599,7 +598,7 @@ void test_config_write__preserves_entry_with_name_only(void)
 	cl_git_pass(git_futils_readbuffer(&newfile, file_name));
 	cl_assert_equal_s("[section \"foo\"]\n\tname\n\tother = otherval\n[newsection]\n\tnewname = new_value\n", newfile.ptr);
 
-	git_buf_dispose(&newfile);
+	git_str_dispose(&newfile);
 	git_config_free(cfg);
 }
 
@@ -607,7 +606,7 @@ void test_config_write__to_empty_file(void)
 {
 	git_config *cfg;
 	const char *filename = "config-file";
-	git_buf result = GIT_BUF_INIT;
+	git_str result = GIT_STR_INIT;
 
 	cl_git_mkfile(filename, "");
 	cl_git_pass(git_config_open_ondisk(&cfg, filename));
@@ -617,14 +616,14 @@ void test_config_write__to_empty_file(void)
 	cl_git_pass(git_futils_readbuffer(&result, "config-file"));
 	cl_assert_equal_s("[section]\n\tname = value\n", result.ptr);
 
-	git_buf_dispose(&result);
+	git_str_dispose(&result);
 }
 
 void test_config_write__to_file_with_only_comment(void)
 {
 	git_config *cfg;
 	const char *filename = "config-file";
-	git_buf result = GIT_BUF_INIT;
+	git_str result = GIT_STR_INIT;
 
 	cl_git_mkfile(filename, "\n\n");
 	cl_git_pass(git_config_open_ondisk(&cfg, filename));
@@ -634,7 +633,7 @@ void test_config_write__to_file_with_only_comment(void)
 	cl_git_pass(git_futils_readbuffer(&result, "config-file"));
 	cl_assert_equal_s("\n\n[section]\n\tname = value\n", result.ptr);
 
-	git_buf_dispose(&result);
+	git_str_dispose(&result);
 }
 
 void test_config_write__locking(void)
@@ -699,7 +698,7 @@ void test_config_write__repeated(void)
 {
 	const char *filename = "config-repeated";
 	git_config *cfg;
-	git_buf result = GIT_BUF_INIT;
+	git_str result = GIT_STR_INIT;
 	const char *expected = "[sample \"prefix\"]\n\
 \tsetting1 = someValue1\n\
 \tsetting2 = someValue2\n\
@@ -717,7 +716,7 @@ void test_config_write__repeated(void)
 
 	cl_git_pass(git_futils_readbuffer(&result, filename));
 	cl_assert_equal_s(expected, result.ptr);
-	git_buf_dispose(&result);
+	git_str_dispose(&result);
 
 	git_config_free(cfg);
 }
@@ -726,7 +725,7 @@ void test_config_write__preserve_case(void)
 {
 	const char *filename = "config-preserve-case";
 	git_config *cfg;
-	git_buf result = GIT_BUF_INIT;
+	git_str result = GIT_STR_INIT;
 	const char *expected = "[sOMe]\n" \
 		"\tThInG = foo\n" \
 		"\tOtheR = thing\n";
@@ -740,7 +739,7 @@ void test_config_write__preserve_case(void)
 
 	cl_git_pass(git_futils_readbuffer(&result, filename));
 	cl_assert_equal_s(expected, result.ptr);
-	git_buf_dispose(&result);
+	git_str_dispose(&result);
 
 	git_config_free(cfg);
 }