1 files changed, 87 insertions, 1 deletions

diff --git a/run-command.c b/run-command.c
index 31fc5ea86e..84899e423f 100644
--- a/run-command.c
+++ b/run-command.c
@@ -6,6 +6,7 @@
 #include "thread-utils.h"
 #include "strbuf.h"
 #include "string-list.h"
+#include "quote.h"
 
 void child_process_init(struct child_process *child)
 {
@@ -556,6 +557,90 @@ static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
 	return code;
 }
 
+static void trace_add_env(struct strbuf *dst, const char *const *deltaenv)
+{
+	struct string_list envs = STRING_LIST_INIT_DUP;
+	const char *const *e;
+	int i;
+	int printed_unset = 0;
+
+	/* Last one wins, see run-command.c:prep_childenv() for context */
+	for (e = deltaenv; e && *e; e++) {
+		struct strbuf key = STRBUF_INIT;
+		char *equals = strchr(*e, '=');
+
+		if (equals) {
+			strbuf_add(&key, *e, equals - *e);
+			string_list_insert(&envs, key.buf)->util = equals + 1;
+		} else {
+			string_list_insert(&envs, *e)->util = NULL;
+		}
+		strbuf_release(&key);
+	}
+
+	/* "unset X Y...;" */
+	for (i = 0; i < envs.nr; i++) {
+		const char *var = envs.items[i].string;
+		const char *val = envs.items[i].util;
+
+		if (val || !getenv(var))
+			continue;
+
+		if (!printed_unset) {
+			strbuf_addstr(dst, " unset");
+			printed_unset = 1;
+		}
+		strbuf_addf(dst, " %s", var);
+	}
+	if (printed_unset)
+		strbuf_addch(dst, ';');
+
+	/* ... followed by "A=B C=D ..." */
+	for (i = 0; i < envs.nr; i++) {
+		const char *var = envs.items[i].string;
+		const char *val = envs.items[i].util;
+		const char *oldval;
+
+		if (!val)
+			continue;
+
+		oldval = getenv(var);
+		if (oldval && !strcmp(val, oldval))
+			continue;
+
+		strbuf_addf(dst, " %s=", var);
+		sq_quote_buf_pretty(dst, val);
+	}
+	string_list_clear(&envs, 0);
+}
+
+static void trace_run_command(const struct child_process *cp)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	if (!trace_want(&trace_default_key))
+		return;
+
+	strbuf_addstr(&buf, "trace: run_command:");
+	if (cp->dir) {
+		strbuf_addstr(&buf, " cd ");
+		sq_quote_buf_pretty(&buf, cp->dir);
+		strbuf_addch(&buf, ';');
+	}
+	/*
+	 * The caller is responsible for initializing cp->env from
+	 * cp->env_array if needed. We only check one place.
+	 */
+	if (cp->env)
+		trace_add_env(&buf, cp->env);
+	if (cp->git_cmd)
+		strbuf_addstr(&buf, " git");
+	sq_quote_argv_pretty(&buf, cp->argv);
+
+	trace_printf("%s", buf.buf);
+	strbuf_release(&buf);
+}
+
 int start_command(struct child_process *cmd)
 {
 	int need_in, need_out, need_err;
@@ -624,7 +709,8 @@ fail_pipe:
 		cmd->err = fderr[0];
 	}
 
-	trace_argv_printf(cmd->argv, "trace: run_command:");
+	trace_run_command(cmd);
+
 	fflush(NULL);
 
 #ifndef GIT_WINDOWS_NATIVE