Merge branch 'maint'

* maint:
  Revert "core.abbrevguard: Ensure short object names stay unique a bit longer"

Documentation/config.txt

@@ -376,15 +376,6 @@ core.warnAmbiguousRefs::
 	If true, git will warn you if the ref name you passed it is ambiguous
 	and might match multiple refs in the .git/refs/ tree. True by default.
 
-core.abbrevguard::
-	Even though git makes sure that it uses enough hexdigits to show
-	an abbreviated object name unambiguously, as more objects are
-	added to the repository over time, a short name that used to be
-	unique will stop being unique.  Git uses this many extra hexdigits
-	that are more than necessary to make the object name currently
-	unique, in the hope that its output will stay unique a bit longer.
-	Defaults to 0.
-
 core.compression::
 	An integer -1..9, indicating a default compression level.
 	-1 is the zlib default. 0 means no compression,

cache.h

@@ -560,7 +560,6 @@ extern int assume_unchanged;
 extern int prefer_symlink_refs;
 extern int log_all_ref_updates;
 extern int warn_ambiguous_refs;
-extern int unique_abbrev_extra_length;
 extern int shared_repository;
 extern const char *apply_default_whitespace;
 extern const char *apply_default_ignorewhitespace;

config.c

@@ -499,13 +499,6 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
-	if (!strcmp(var, "core.abbrevguard")) {
-		unique_abbrev_extra_length = git_config_int(var, value);
-		if (unique_abbrev_extra_length < 0)
-			unique_abbrev_extra_length = 0;
-		return 0;
-	}
-
 	if (!strcmp(var, "core.bare")) {
 		is_bare_repository_cfg = git_config_bool(var, value);
 		return 0;

environment.c

@@ -21,7 +21,6 @@ int prefer_symlink_refs;
 int is_bare_repository_cfg = -1; /* unspecified */
 int log_all_ref_updates = -1; /* unspecified */
 int warn_ambiguous_refs = 1;
-int unique_abbrev_extra_length;
 int repository_format_version;
 const char *git_commit_encoding;
 const char *git_log_output_encoding;

sha1_name.c

@@ -208,9 +208,7 @@ const char *find_unique_abbrev(const unsigned char *sha1, int len)
 		if (exists
 		    ? !status
 		    : status == SHORT_NAME_NOT_FOUND) {
-			int cut_at = len + unique_abbrev_extra_length;
-			cut_at = (cut_at < 40) ? cut_at : 40;
-			hex[cut_at] = 0;
+			hex[len] = 0;
 			return hex;
 		}
 		len++;