video(wayland): use both --icon and --icon-name for Zenity (#7897)

video(wayland): use both --icon and --icon-name for Zenity

Many distros ship an older version of Zenity that supports GTK3, while some distros ship newer version of Zenity which uses libadwaita.

This command tries to use --icon and fall back to --icon-name when it fails.

src/video/wayland/SDL_waylandmessagebox.c

@@ -33,160 +33,218 @@
 
 #include "SDL_waylandmessagebox.h"
 
+#define ZENITY_VERSION_LEN 32 /* Number of bytes to read from zenity --version (including NUL)*/
+
 #define MAX_BUTTONS 8 /* Maximum number of buttons supported */
 
-int Wayland_ShowMessageBox(const SDL_MessageBoxData *messageboxdata, int *buttonid)
-{
-    int fd_pipe[2]; /* fd_pipe[0]: read end of pipe, fd_pipe[1]: write end of pipe */
+static int run_zenity(const char **args, int fd_pipe[2]) {
+    int status;
     pid_t pid1;
 
+    pid1 = fork();
+    if (pid1 == 0) { /* child process */
+        close(fd_pipe[0]); /* no reading from pipe */
+        /* write stdout in pipe */
+        if (dup2(fd_pipe[1], STDOUT_FILENO) == -1) {
+            _exit(128);
+        }
+
+        /* const casting argv is fine:
+         * https://pubs.opengroup.org/onlinepubs/9699919799/functions/fexecve.html -> rational
+         */
+        execvp("zenity", (char **)args);
+        _exit(129);
+    } else if (pid1 < 0) { /* fork() failed */
+        return SDL_SetError("fork() failed: %s", strerror(errno));
+    } else { /* parent process */
+        close(fd_pipe[1]); /* no writing to the pipe */
+        if (waitpid(pid1, &status, 0) != pid1) {
+            return SDL_SetError("Waiting on zenity failed: %s", strerror(errno));
+        }
+
+        if (!WIFEXITED(status)) {
+            return SDL_SetError("zenity failed for some reason");
+        }
+
+        if (WEXITSTATUS(status) >= 128) {
+            return SDL_SetError("zenity reported error or failed to launch: %d", WEXITSTATUS(status));
+        }
+
+        return 0; /* success! */
+    }
+}
+
+static int get_zenity_version(int *major, int *minor) {
+    int fd_pipe[2]; /* fd_pipe[0]: read end of pipe, fd_pipe[1]: write end of pipe */
+    const char *argv[] = { "zenity", "--version", NULL };
+
+    if (pipe(fd_pipe) != 0) { /* create a pipe */
+        return SDL_SetError("pipe() failed: %s", strerror(errno));
+    }
+
+    if (run_zenity(argv, fd_pipe) == 0) {
+        FILE *outputfp = NULL;
+        char version_str[ZENITY_VERSION_LEN];
+        char *version_ptr = NULL, *end_ptr = NULL;
+        int tmp;
+
+        outputfp = fdopen(fd_pipe[0], "r");
+        if (outputfp == NULL) {
+            close(fd_pipe[0]);
+            return SDL_SetError("failed to open pipe for reading: %s", strerror(errno));
+        }
+
+        version_ptr = fgets(version_str, ZENITY_VERSION_LEN, outputfp);
+        (void)fclose(outputfp); /* will close underlying fd */
+
+        /* we expect the version string is in the form of MAJOR.MINOR.MICRO
+         * as described in meson.build. We'll ignore everything after that.
+         */
+        tmp = (int) SDL_strtol(version_ptr, &end_ptr, 10);
+        if (tmp == 0 && end_ptr == version_ptr) {
+            return SDL_SetError("failed to get zenity major version number");
+        }
+        *major = tmp;
+
+        version_ptr = end_ptr + 1; /* skip the dot */
+        tmp = (int) SDL_strtol(version_ptr, &end_ptr, 10);
+        if (tmp == 0 && end_ptr == version_ptr) {
+            return SDL_SetError("failed to get zenity minor version number");
+        }
+        *minor = tmp;
+
+        return 0; /* success */
+    }
+
+    close(fd_pipe[0]);
+    close(fd_pipe[1]);
+    return -1; /* run_zenity should've called SDL_SetError() */
+}
+
+int Wayland_ShowMessageBox(const SDL_MessageBoxData *messageboxdata, int *buttonid) {
+    int fd_pipe[2]; /* fd_pipe[0]: read end of pipe, fd_pipe[1]: write end of pipe */
+    int zenity_major = 0, zenity_minor = 0, output_len = 0;
+    int argc = 5, i;
+    const char *argv[5 + 2 /* icon name */ + 2 /* title */ + 2 /* message */ + 2 * MAX_BUTTONS + 1 /* NULL */] = {
+        "zenity", "--question", "--switch", "--no-wrap", "--no-markup"
+    };
+
     if (messageboxdata->numbuttons > MAX_BUTTONS) {
         return SDL_SetError("Too many buttons (%d max allowed)", MAX_BUTTONS);
     }
 
+    /* get zenity version so we know which arg to use */
+    if (get_zenity_version(&zenity_major, &zenity_minor) != 0) {
+        return -1; /* get_zenity_version() calls SDL_SetError(), so message is already set */
+    }
+
     if (pipe(fd_pipe) != 0) { /* create a pipe */
         return SDL_SetError("pipe() failed: %s", strerror(errno));
     }
 
-    pid1 = fork();
-    if (pid1 == 0) { /* child process */
-        int argc = 5, i;
-        const char *argv[5 + 2 /* icon name */ + 2 /* title */ + 2 /* message */ + 2 * MAX_BUTTONS + 1 /* NULL */] = {
-            "zenity", "--question", "--switch", "--no-wrap", "--no-markup"
-        };
+    /* https://gitlab.gnome.org/GNOME/zenity/-/commit/c686bdb1b45e95acf010efd9ca0c75527fbb4dea
+     * This commit removed --icon-name without adding a deprecation notice.
+     * We need to handle it gracefully, otherwise no message box will be shown.
+     */
+    argv[argc++] = zenity_major > 3 || (zenity_major == 3 && zenity_minor >= 90) ? "--icon" : "--icon-name";
+    switch (messageboxdata->flags) {
+    case SDL_MESSAGEBOX_ERROR:
+        argv[argc++] = "dialog-error";
+        break;
+    case SDL_MESSAGEBOX_WARNING:
+        argv[argc++] = "dialog-warning";
+        break;
+    case SDL_MESSAGEBOX_INFORMATION:
+    default:
+        argv[argc++] = "dialog-information";
+        break;
+    }
 
-        close(fd_pipe[0]); /* no reading from pipe */
-        /* write stdout in pipe */
-        if (dup2(fd_pipe[1], STDOUT_FILENO) == -1) {
-            _exit(128);
+    if (messageboxdata->title && messageboxdata->title[0]) {
+        argv[argc++] = "--title";
+        argv[argc++] = messageboxdata->title;
+    } else {
+        argv[argc++] = "--title=\"\"";
+    }
+
+    if (messageboxdata->message && messageboxdata->message[0]) {
+        argv[argc++] = "--text";
+        argv[argc++] = messageboxdata->message;
+    } else {
+        argv[argc++] = "--text=\"\"";
+    }
+
+    for (i = 0; i < messageboxdata->numbuttons; ++i) {
+        if (messageboxdata->buttons[i].text && messageboxdata->buttons[i].text[0]) {
+            int len = SDL_strlen(messageboxdata->buttons[i].text);
+            if (len > output_len) {
+                output_len = len;
+            }
+
+            argv[argc++] = "--extra-button";
+            argv[argc++] = messageboxdata->buttons[i].text;
+        } else {
+            argv[argc++] = "--extra-button=\"\"";
         }
+    }
+    argv[argc] = NULL;
+
+    if (run_zenity(argv, fd_pipe) == 0) {
+        FILE *outputfp = NULL;
+        char *output = NULL;
+        char *tmp = NULL;
 
-        argv[argc++] = "--icon-name";
-        switch (messageboxdata->flags) {
-        case SDL_MESSAGEBOX_ERROR:
-            argv[argc++] = "dialog-error";
-            break;
-        case SDL_MESSAGEBOX_WARNING:
-            argv[argc++] = "dialog-warning";
-            break;
-        case SDL_MESSAGEBOX_INFORMATION:
-        default:
-            argv[argc++] = "dialog-information";
-            break;
+        if (buttonid == NULL) {
+            /* if we don't need buttonid, we can return immediately */
+            close(fd_pipe[0]);
+            return 0; /* success */
         }
+        *buttonid = -1;
 
-        if (messageboxdata->title && messageboxdata->title[0]) {
-            argv[argc++] = "--title";
-            argv[argc++] = messageboxdata->title;
-        } else {
-            argv[argc++] = "--title=\"\"";
+        output = SDL_malloc(output_len + 1);
+        if (output == NULL) {
+            close(fd_pipe[0]);
+            return SDL_OutOfMemory();
         }
+        output[0] = '\0';
 
-        if (messageboxdata->message && messageboxdata->message[0]) {
-            argv[argc++] = "--text";
-            argv[argc++] = messageboxdata->message;
-        } else {
-            argv[argc++] = "--text=\"\"";
+        outputfp = fdopen(fd_pipe[0], "r");
+        if (outputfp == NULL) {
+            SDL_free(output);
+            close(fd_pipe[0]);
+            return SDL_SetError("Couldn't open pipe for reading: %s", strerror(errno));
         }
+        tmp = fgets(output, output_len + 1, outputfp);
+        (void)fclose(outputfp);
 
-        for (i = 0; i < messageboxdata->numbuttons; ++i) {
-            if (messageboxdata->buttons[i].text && messageboxdata->buttons[i].text[0]) {
-                argv[argc++] = "--extra-button";
-                argv[argc++] = messageboxdata->buttons[i].text;
-            } else {
-                argv[argc++] = "--extra-button=\"\"";
-            }
+        if ((tmp == NULL) || (*tmp == '\0') || (*tmp == '\n')) {
+            SDL_free(output);
+            return 0; /* User simply closed the dialog */
         }
-        argv[argc] = NULL;
 
-        /* const casting argv is fine:
-         * https://pubs.opengroup.org/onlinepubs/9699919799/functions/fexecve.html -> rational
-         */
-        execvp("zenity", (char **)argv);
-        _exit(129);
-    } else if (pid1 < 0) {
-        close(fd_pipe[0]);
-        close(fd_pipe[1]);
-        return SDL_SetError("fork() failed: %s", strerror(errno));
-    } else {
-        int status;
-        if (waitpid(pid1, &status, 0) == pid1) {
-            if (WIFEXITED(status)) {
-                if (WEXITSTATUS(status) < 128) {
-                    int i;
-                    size_t output_len = 1;
-                    char *output = NULL;
-                    char *tmp = NULL;
-                    FILE *outputfp = NULL;
-
-                    close(fd_pipe[1]); /* no writing to pipe */
-                    /* At this point, if no button ID is needed, we can just bail as soon as the
-                     * process has completed.
-                     */
-                    if (buttonid == NULL) {
-                        close(fd_pipe[0]);
-                        return 0;
-                    }
-                    *buttonid = -1;
-
-                    /* find button with longest text */
-                    for (i = 0; i < messageboxdata->numbuttons; ++i) {
-                        if (messageboxdata->buttons[i].text != NULL) {
-                            const size_t button_len = SDL_strlen(messageboxdata->buttons[i].text);
-                            if (button_len > output_len) {
-                                output_len = button_len;
-                            }
-                        }
-                    }
-                    output = SDL_malloc(output_len + 1);
-                    if (output == NULL) {
-                        close(fd_pipe[0]);
-                        return SDL_OutOfMemory();
-                    }
-                    output[0] = '\0';
-
-                    outputfp = fdopen(fd_pipe[0], "r");
-                    if (outputfp == NULL) {
-                        SDL_free(output);
-                        close(fd_pipe[0]);
-                        return SDL_SetError("Couldn't open pipe for reading: %s", strerror(errno));
-                    }
-                    tmp = fgets(output, output_len + 1, outputfp);
-                    (void)fclose(outputfp);
-
-                    if ((tmp == NULL) || (*tmp == '\0') || (*tmp == '\n')) {
-                        SDL_free(output);
-                        return 0; /* User simply closed the dialog */
-                    }
-
-                    /* It likes to add a newline... */
-                    tmp = SDL_strrchr(output, '\n');
-                    if (tmp != NULL) {
-                        *tmp = '\0';
-                    }
-
-                    /* Check which button got pressed */
-                    for (i = 0; i < messageboxdata->numbuttons; i += 1) {
-                        if (messageboxdata->buttons[i].text != NULL) {
-                            if (SDL_strcmp(output, messageboxdata->buttons[i].text) == 0) {
-                                *buttonid = messageboxdata->buttons[i].buttonid;
-                                break;
-                            }
-                        }
-                    }
-
-                    SDL_free(output);
-                    return 0; /* success! */
-                } else {
-                    return SDL_SetError("zenity reported error or failed to launch: %d", WEXITSTATUS(status));
+        /* It likes to add a newline... */
+        tmp = SDL_strrchr(output, '\n');
+        if (tmp != NULL) {
+            *tmp = '\0';
+        }
+
+        /* Check which button got pressed */
+        for (i = 0; i < messageboxdata->numbuttons; i += 1) {
+            if (messageboxdata->buttons[i].text != NULL) {
+                if (SDL_strcmp(output, messageboxdata->buttons[i].text) == 0) {
+                    *buttonid = messageboxdata->buttons[i].buttonid;
+                    break;
                 }
-            } else {
-                return SDL_SetError("zenity failed for some reason");
             }
-        } else {
-            return SDL_SetError("Waiting on zenity failed: %s", strerror(errno));
         }
+
+        SDL_free(output);
+        return 0; /* success! */
     }
+
+    close(fd_pipe[0]);
+    close(fd_pipe[1]);
+    return -1; /* run_zenity() calls SDL_SetError(), so message is already set */
 }
 
 #endif /* SDL_VIDEO_DRIVER_WAYLAND */