Replace VLA by dynamic allocation

And increase the command buffer size.

Refs #1358 <https://github.com/Genymobile/scrcpy/issues/1358#issuecomment-862989748>
PR #2405 <https://github.com/Genymobile/scrcpy/pull/2405>

Signed-off-by: Romain Vimont <rom@rom1v.com>

app/src/adb.c

@@ -81,14 +81,20 @@ show_adb_installation_msg() {
 
 static void
 show_adb_err_msg(enum process_result err, const char *const argv[]) {
-    char buf[512];
+#define MAX_COMMAND_STRING_LEN 1024
+    char *buf = malloc(MAX_COMMAND_STRING_LEN);
+    if (!buf) {
+        LOGE("Failed to execute (could not allocate error message)");
+        return;
+    }
+
     switch (err) {
         case PROCESS_ERROR_GENERIC:
-            argv_to_string(argv, buf, sizeof(buf));
+            argv_to_string(argv, buf, MAX_COMMAND_STRING_LEN);
             LOGE("Failed to execute: %s", buf);
             break;
         case PROCESS_ERROR_MISSING_BINARY:
-            argv_to_string(argv, buf, sizeof(buf));
+            argv_to_string(argv, buf, MAX_COMMAND_STRING_LEN);
             LOGE("Command not found: %s", buf);
             LOGE("(make 'adb' accessible from your PATH or define its full"
                  "path in the ADB environment variable)");
@@ -98,29 +104,38 @@ show_adb_err_msg(enum process_result err, const char *const argv[]) {
             // do nothing
             break;
     }
+
+    free(buf);
 }
 
 process_t
 adb_execute(const char *serial, const char *const adb_cmd[], size_t len) {
-    const char *cmd[len + 4];
     int i;
     process_t process;
-    cmd[0] = get_adb_command();
+
+    const char **argv = malloc((len + 4) * sizeof(*argv));
+    if (!argv) {
+        return PROCESS_NONE;
+    }
+
+    argv[0] = get_adb_command();
     if (serial) {
-        cmd[1] = "-s";
-        cmd[2] = serial;
+        argv[1] = "-s";
+        argv[2] = serial;
         i = 3;
     } else {
         i = 1;
     }
 
-    memcpy(&cmd[i], adb_cmd, len * sizeof(const char *));
-    cmd[len + i] = NULL;
-    enum process_result r = process_execute(cmd, &process);
+    memcpy(&argv[i], adb_cmd, len * sizeof(const char *));
+    argv[len + i] = NULL;
+    enum process_result r = process_execute(argv, &process);
     if (r != PROCESS_SUCCESS) {
-        show_adb_err_msg(r, cmd);
-        return PROCESS_NONE;
+        show_adb_err_msg(r, argv);
+        process = PROCESS_NONE;
     }
+
+    free(argv);
     return process;
 }
 

app/src/sys/win/process.c

@@ -6,7 +6,9 @@
 #include "util/log.h"
 #include "util/str_util.h"
 
-static int
+#define CMD_MAX_LEN 8192
+
+static bool
 build_cmd(char *cmd, size_t len, const char *const argv[]) {
     // Windows command-line parsing is WTF:
     // <http://daviddeley.com/autohotkey/parameters/parameters.htm#WINPASS>
@@ -15,9 +17,9 @@ build_cmd(char *cmd, size_t len, const char *const argv[]) {
     size_t ret = xstrjoin(cmd, argv, ' ', len);
     if (ret >= len) {
         LOGE("Command too long (%" PRIsizet " chars)", len - 1);
-        return -1;
+        return false;
     }
-    return 0;
+    return true;
 }
 
 enum process_result
@@ -27,13 +29,14 @@ process_execute(const char *const argv[], HANDLE *handle) {
     memset(&si, 0, sizeof(si));
     si.cb = sizeof(si);
 
-    char cmd[256];
-    if (build_cmd(cmd, sizeof(cmd), argv)) {
+    char *cmd = malloc(CMD_MAX_LEN);
+    if (!cmd || !build_cmd(cmd, CMD_MAX_LEN, argv)) {
         *handle = NULL;
         return PROCESS_ERROR_GENERIC;
     }
 
     wchar_t *wide = utf8_to_wide_char(cmd);
+    free(cmd);
     if (!wide) {
         LOGC("Could not allocate wide char string");
         return PROCESS_ERROR_GENERIC;