Load ADB value using sc_get_env()

Contrary to getenv(), the result of sc_get_env() is encoded in UTF-8 on
all platforms. Since it is allocated, it requires an explicit init() and
destroy() functions.

PR #5560 <https://github.com/Genymobile/scrcpy/pull/5560>

app/src/adb/adb.c

@@ -7,6 +7,7 @@
 
 #include "adb_device.h"
 #include "adb_parser.h"
+#include "util/env.h"
 #include "util/file.h"
 #include "util/log.h"
 #include "util/process_intr.h"
@@ -24,15 +25,31 @@
  */
 #define SC_ADB_COMMAND(...) { sc_adb_get_executable(), __VA_ARGS__, NULL }
 
-static const char *adb_executable;
+static char *adb_executable;
+
+bool
+sc_adb_init(void) {
+    adb_executable = sc_get_env("ADB");
+    if (adb_executable) {
+        return true;
+    }
+
+    adb_executable = strdup("adb");
+    if (!adb_executable) {
+        LOG_OOM();
+        return false;
+    }
+
+    return true;
+}
+
+void
+sc_adb_destroy(void) {
+    free(adb_executable);
+}
 
 const char *
 sc_adb_get_executable(void) {
-    if (!adb_executable) {
-        adb_executable = getenv("ADB");
-        if (!adb_executable)
-            adb_executable = "adb";
-    }
     return adb_executable;
 }
 

app/src/adb/adb.h

@@ -15,6 +15,12 @@
 
 #define SC_ADB_SILENT (SC_ADB_NO_STDOUT | SC_ADB_NO_STDERR | SC_ADB_NO_LOGERR)
 
+bool
+sc_adb_init(void);
+
+void
+sc_adb_destroy(void);
+
 const char *
 sc_adb_get_executable(void);
 

app/src/server.c

@@ -485,14 +485,21 @@ sc_server_init(struct sc_server *server, const struct sc_server_params *params,
     // end of the program
     server->params = *params;
 
-    bool ok = sc_mutex_init(&server->mutex);
+    bool ok = sc_adb_init();
     if (!ok) {
         return false;
     }
 
+    ok = sc_mutex_init(&server->mutex);
+    if (!ok) {
+        sc_adb_destroy();
+        return false;
+    }
+
     ok = sc_cond_init(&server->cond_stopped);
     if (!ok) {
         sc_mutex_destroy(&server->mutex);
+        sc_adb_destroy();
         return false;
     }
 
@@ -500,6 +507,7 @@ sc_server_init(struct sc_server *server, const struct sc_server_params *params,
     if (!ok) {
         sc_cond_destroy(&server->cond_stopped);
         sc_mutex_destroy(&server->mutex);
+        sc_adb_destroy();
         return false;
     }
 
@@ -1141,4 +1149,6 @@ sc_server_destroy(struct sc_server *server) {
     sc_intr_destroy(&server->intr);
     sc_cond_destroy(&server->cond_stopped);
     sc_mutex_destroy(&server->mutex);
+
+    sc_adb_destroy();
 }

app/src/usb/scrcpy_otg.c

@@ -95,9 +95,14 @@ scrcpy_otg(struct scrcpy_options *options) {
     // On Windows, only one process could open a USB device
     // <https://github.com/Genymobile/scrcpy/issues/2773>
     LOGI("Killing adb server (if any)...");
-    unsigned flags = SC_ADB_NO_STDOUT | SC_ADB_NO_STDERR | SC_ADB_NO_LOGERR;
+    if (sc_adb_init()) {
-    // uninterruptible (intr == NULL), but in practice it's very quick
+        unsigned flags = SC_ADB_NO_STDOUT | SC_ADB_NO_STDERR | SC_ADB_NO_LOGERR;
-    sc_adb_kill_server(NULL, flags);
+        // uninterruptible (intr == NULL), but in practice it's very quick
+        sc_adb_kill_server(NULL, flags);
+        sc_adb_destroy();
+    } else {
+        LOGW("Could not call adb executable, adb server not killed");
+    }
 #endif
 
     static const struct sc_usb_callbacks cbs = {