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, 18 insertions, 19 deletions

diff --git a/tests/diff/stats.c b/tests/diff/stats.c
index 54572672c..f69dba9b3 100644
--- a/tests/diff/stats.c
+++ b/tests/diff/stats.c
@@ -1,7 +1,6 @@
 #include "clar.h"
 #include "clar_libgit2.h"
 
-#include "buffer.h"
 #include "commit.h"
 #include "diff.h"
 #include "diff_generate.h"
@@ -53,11 +52,11 @@ void test_diff_stats__stat(void)
 	cl_assert_equal_sz(3, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert(strcmp(git_buf_cstr(&buf), stat) == 0);
+	cl_assert(strcmp(buf.ptr, stat) == 0);
 	git_buf_dispose(&buf);
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 80));
-	cl_assert(strcmp(git_buf_cstr(&buf), stat) == 0);
+	cl_assert(strcmp(buf.ptr, stat) == 0);
 	git_buf_dispose(&buf);
 }
 
@@ -77,7 +76,7 @@ void test_diff_stats__multiple_hunks(void)
 	cl_assert_equal_sz(4, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -92,7 +91,7 @@ void test_diff_stats__numstat(void)
 		&_stats, "cd471f0d8770371e1bc78bcbb38db4c7e4106bd2", false);
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_NUMBER, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -110,7 +109,7 @@ void test_diff_stats__shortstat(void)
 	cl_assert_equal_sz(3, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_SHORT, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -128,7 +127,7 @@ void test_diff_stats__shortstat_noinsertions(void)
 	cl_assert_equal_sz(2, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_SHORT, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -146,7 +145,7 @@ void test_diff_stats__shortstat_nodeletions(void)
 	cl_assert_equal_sz(0, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_SHORT, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -166,7 +165,7 @@ void test_diff_stats__rename(void)
 	cl_assert_equal_sz(1, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -186,7 +185,7 @@ void test_diff_stats__rename_nochanges(void)
 	cl_assert_equal_sz(0, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -206,7 +205,7 @@ void test_diff_stats__rename_and_modifiy(void)
 	cl_assert_equal_sz(1, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -225,7 +224,7 @@ void test_diff_stats__rename_in_subdirectory(void)
 	cl_assert_equal_sz(0, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -247,7 +246,7 @@ void test_diff_stats__rename_no_find(void)
 	cl_assert_equal_sz(10, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -269,7 +268,7 @@ void test_diff_stats__rename_nochanges_no_find(void)
 	cl_assert_equal_sz(13, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -290,7 +289,7 @@ void test_diff_stats__rename_and_modify_no_find(void)
 	cl_assert_equal_sz(8, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -309,7 +308,7 @@ void test_diff_stats__binary(void)
 	cl_assert_equal_sz(0, git_diff_stats_deletions(_stats));
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -323,7 +322,7 @@ void test_diff_stats__binary_numstat(void)
 		&_stats, "8d7523f6fcb2404257889abe0d96f093d9f524f9", false);
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_NUMBER, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -339,7 +338,7 @@ void test_diff_stats__mode_change(void)
 		&_stats, "7ade76dd34bba4733cf9878079f9fd4a456a9189", false);
 
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL | GIT_DIFF_STATS_INCLUDE_SUMMARY, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 	git_buf_dispose(&buf);
 }
 
@@ -372,7 +371,7 @@ void test_diff_stats__new_file(void)
 	cl_git_pass(git_diff_from_buffer(&diff, input, strlen(input)));
 	cl_git_pass(git_diff_get_stats(&_stats, diff));
 	cl_git_pass(git_diff_stats_to_buf(&buf, _stats, GIT_DIFF_STATS_FULL | GIT_DIFF_STATS_INCLUDE_SUMMARY, 0));
-	cl_assert_equal_s(stat, git_buf_cstr(&buf));
+	cl_assert_equal_s(stat, buf.ptr);
 
 	git_buf_dispose(&buf);
 	git_diff_free(diff);