Processing (Linux): don't use /proc/pid/exe as exePath when the file is not executable (no permission)

Author: CarterLi

src/common/impl/FFPlatform_unix.c

@@ -30,7 +30,7 @@ static void getExePath(FFPlatform* platform) {
     char exePath[PATH_MAX];
 #if defined(__linux__) || defined(__GNU__)
     ssize_t exePathLen = readlink("/proc/self/exe", exePath, sizeof(exePath) - 1);
-    if (exePathLen >= 0) {
+    if (exePathLen > 0) {
         exePath[exePathLen] = '\0';
     }
 #elif defined(__APPLE__)
@@ -128,7 +128,7 @@ static void getExePath(FFPlatform* platform) {
     }
 #elif defined(__sun)
     ssize_t exePathLen = readlink("/proc/self/path/a.out", exePath, sizeof(exePath) - 1);
-    if (exePathLen >= 0) {
+    if (exePathLen > 0) {
         exePath[exePathLen] = '\0';
     }
 #elif defined(__HAIKU__)

src/common/impl/processing_linux.c

@@ -269,7 +269,7 @@ void ffProcessGetInfoLinux(pid_t pid, FFstrbuf* processName, FFstrbuf* exe, cons
             }
         }
 
-        if (exePath->length == 0) {
+        if (exePath->length == 0 && access(filePath, X_OK) == 0) {
             ffStrbufSetS(exePath, filePath);
         }
     }