revert(3p/git): Revert merge of git upstream at v2.26.2

This causes cgit to serve error pages, which is undesirable.

This reverts commit 5229c9b232, reversing
changes made to f2b211131f.

third_party/git/trace.h

@@ -4,82 +4,6 @@
 #include "git-compat-util.h"
 #include "strbuf.h"
 
-/**
- * The trace API can be used to print debug messages to stderr or a file. Trace
- * code is inactive unless explicitly enabled by setting `GIT_TRACE*` environment
- * variables.
- *
- * The trace implementation automatically adds `timestamp file:line ... \n` to
- * all trace messages. E.g.:
- *
- * ------------
- * 23:59:59.123456 git.c:312               trace: built-in: git 'foo'
- * 00:00:00.000001 builtin/foo.c:99        foo: some message
- * ------------
- *
- * Bugs & Caveats
- * --------------
- *
- * GIT_TRACE_* environment variables can be used to tell Git to show
- * trace output to its standard error stream. Git can often spawn a pager
- * internally to run its subcommand and send its standard output and
- * standard error to it.
- *
- * Because GIT_TRACE_PERFORMANCE trace is generated only at the very end
- * of the program with atexit(), which happens after the pager exits, it
- * would not work well if you send its log to the standard error output
- * and let Git spawn the pager at the same time.
- *
- * As a work around, you can for example use '--no-pager', or set
- * GIT_TRACE_PERFORMANCE to another file descriptor which is redirected
- * to stderr, or set GIT_TRACE_PERFORMANCE to a file specified by its
- * absolute path.
- *
- * For example instead of the following command which by default may not
- * print any performance information:
- *
- * ------------
- * GIT_TRACE_PERFORMANCE=2 git log -1
- * ------------
- *
- * you may want to use:
- *
- * ------------
- * GIT_TRACE_PERFORMANCE=2 git --no-pager log -1
- * ------------
- *
- * or:
- *
- * ------------
- * GIT_TRACE_PERFORMANCE=3 3>&2 git log -1
- * ------------
- *
- * or:
- *
- * ------------
- * GIT_TRACE_PERFORMANCE=/path/to/log/file git log -1
- * ------------
- *
- */
-
-/**
- * Defines a trace key (or category). The default (for API functions that
- * don't take a key) is `GIT_TRACE`.
- *
- * E.g. to define a trace key controlled by environment variable `GIT_TRACE_FOO`:
- *
- * ------------
- * static struct trace_key trace_foo = TRACE_KEY_INIT(FOO);
- *
- * static void trace_print_foo(const char *message)
- * {
- * 	trace_printf_key(&trace_foo, "%s", message);
- * }
- * ------------
- *
- * Note: don't use `const` as the trace implementation stores internal state in
- * the `trace_key` structure.
- */
 struct trace_key {
 	const char * const key;
 	int fd;
@@ -94,84 +18,31 @@ extern struct trace_key trace_perf_key;
 extern struct trace_key trace_setup_key;
 
 void trace_repo_setup(const char *prefix);
-
-/**
- * Checks whether the trace key is enabled. Used to prevent expensive
- * string formatting before calling one of the printing APIs.
- */
 int trace_want(struct trace_key *key);
-
-/**
- * Disables tracing for the specified key, even if the environment variable
- * was set.
- */
 void trace_disable(struct trace_key *key);
-
-/**
- * Returns nanoseconds since the epoch (01/01/1970), typically used
- * for performance measurements.
- * Currently there are high precision timer implementations for Linux (using
- * `clock_gettime(CLOCK_MONOTONIC)`) and Windows (`QueryPerformanceCounter`).
- * Other platforms use `gettimeofday` as time source.
- */
 uint64_t getnanotime(void);
-
 void trace_command_performance(const char **argv);
 void trace_verbatim(struct trace_key *key, const void *buf, unsigned len);
 uint64_t trace_performance_enter(void);
 
 #ifndef HAVE_VARIADIC_MACROS
 
-/**
- * Prints a formatted message, similar to printf.
- */
 __attribute__((format (printf, 1, 2)))
 void trace_printf(const char *format, ...);
 
 __attribute__((format (printf, 2, 3)))
 void trace_printf_key(struct trace_key *key, const char *format, ...);
 
-/**
- * Prints a formatted message, followed by a quoted list of arguments.
- */
 __attribute__((format (printf, 2, 3)))
 void trace_argv_printf(const char **argv, const char *format, ...);
 
-/**
- * Prints the strbuf, without additional formatting (i.e. doesn't
- * choke on `%` or even `\0`).
- */
 void trace_strbuf(struct trace_key *key, const struct strbuf *data);
 
-/**
- * Prints elapsed time (in nanoseconds) if GIT_TRACE_PERFORMANCE is enabled.
- *
- * Example:
- * ------------
- * uint64_t t = 0;
- * for (;;) {
- * 	// ignore
- * t -= getnanotime();
- * // code section to measure
- * t += getnanotime();
- * // ignore
- * }
- * trace_performance(t, "frotz");
- * ------------
- */
+/* Prints elapsed time (in nanoseconds) if GIT_TRACE_PERFORMANCE is enabled. */
 __attribute__((format (printf, 2, 3)))
 void trace_performance(uint64_t nanos, const char *format, ...);
 
-/**
- * Prints elapsed time since 'start' if GIT_TRACE_PERFORMANCE is enabled.
- *
- * Example:
- * ------------
- * uint64_t start = getnanotime();
- * // code section to measure
- * trace_performance_since(start, "foobar");
- * ------------
- */
+/* Prints elapsed time since 'start' if GIT_TRACE_PERFORMANCE is enabled. */
 __attribute__((format (printf, 2, 3)))
 void trace_performance_since(uint64_t start, const char *format, ...);