From b7e631791cc0c9af407c9f625047754f6adf369c Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Sun, 28 Nov 2021 22:02:40 +0100
Subject: [PATCH] Add util function to remove trailing '\r'

Depending on the platform and adb versions, the lines output by adb
could end with "\r\r\n". This util function helps to remove all trailing
'\r'.

PR #2827 <https://github.com/Genymobile/scrcpy/pull/2827>
---
 app/src/util/str.c   | 11 +++++++++++
 app/src/util/str.h   | 11 +++++++++++
 app/tests/test_str.c | 15 +++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/app/src/util/str.c b/app/src/util/str.c
index 1564ffe2..70e3f1de 100644
--- a/app/src/util/str.c
+++ b/app/src/util/str.c
@@ -330,3 +330,14 @@ sc_str_index_of_column(const char *s, unsigned col, const char *seps) {
 
     return col == colidx ? (ssize_t) idx : -1;
 }
+
+size_t
+sc_str_remove_trailing_cr(char *s, size_t len) {
+    while (len) {
+        if (s[len - 1] != '\r') {
+            break;
+        }
+        s[--len] = '\0';
+    }
+    return len;
+}
diff --git a/app/src/util/str.h b/app/src/util/str.h
index 2c7d7829..b81764ef 100644
--- a/app/src/util/str.h
+++ b/app/src/util/str.h
@@ -134,4 +134,15 @@ sc_str_truncate(char *data, size_t len, const char *endchars);
 ssize_t
 sc_str_index_of_column(const char *s, unsigned col, const char *seps);
 
+/**
+ * Remove all `\r` at the end of the line
+ *
+ * The line length is provided by `len` (this avoids a call to `strlen()` when
+ * the caller already knows the length).
+ *
+ * Return the new length.
+ */
+size_t
+sc_str_remove_trailing_cr(char *s, size_t len);
+
 #endif
diff --git a/app/tests/test_str.c b/app/tests/test_str.c
index bd976b3c..cc3039e7 100644
--- a/app/tests/test_str.c
+++ b/app/tests/test_str.c
@@ -384,6 +384,20 @@ static void test_index_of_column(void) {
     assert(sc_str_index_of_column("  a bc  d", 1, " ") == 2);
 }
 
+static void test_remove_trailing_cr() {
+    char s[] = "abc\r";
+    sc_str_remove_trailing_cr(s, sizeof(s) - 1);
+    assert(!strcmp(s, "abc"));
+
+    char s2[] = "def\r\r\r\r";
+    sc_str_remove_trailing_cr(s2, sizeof(s2) - 1);
+    assert(!strcmp(s2, "def"));
+
+    char s3[] = "adb\rdef\r";
+    sc_str_remove_trailing_cr(s3, sizeof(s3) - 1);
+    assert(!strcmp(s3, "adb\rdef"));
+}
+
 int main(int argc, char *argv[]) {
     (void) argc;
     (void) argv;
@@ -405,5 +419,6 @@ int main(int argc, char *argv[]) {
     test_wrap_lines();
     test_truncate();
     test_index_of_column();
+    test_remove_trailing_cr();
     return 0;
 }