displayinfo_linux: parse resolution after the name token, validate bounds, accept any modern resolution

src/wg/displayinfo_linux.cpp

@@ -1,25 +1,58 @@
-// src/wg/displayinfo_linux.cpp — Linux implementation of display enumeration.
+// src/wg/displayinfo_linux.cpp - Linux implementation of display enumeration.
 //
 // Uses xrandr subprocess to query connected displays.
-// Parses lines matching: <output-name> connected [primary] <WxH>+<x>+<y>
+// Parses lines matching: <output-name> connected [primary] <WxH>+<x>+<y> ...
 
 #include "displayinfo.h"
 
 #if defined(__linux__)
 
+#include <cctype>
 #include <cstdio>
+#include <cstdlib>
 #include <cstring>
 #include <string>
 #include <vector>
 
 namespace wg {
 
+// Parse "WxH" out of a region of a string.  Returns true on success and fills
+// (w, h) with values that satisfy 640 <= w <= 10000, 480 <= h <= 10000.
+//
+// Searches the whole input.  Caller is expected to have already stripped the
+// leading output-name token so we don't pick up digits in names like "DP-1".
+static bool parseResolution(const char *s, int *w, int *h) {
+    while (*s) {
+        if (std::isdigit(static_cast<unsigned char>(*s))) {
+            int width  = 0;
+            int height = 0;
+            int consumed = 0;
+            if (std::sscanf(s, "%dx%d%n", &width, &height, &consumed) == 2
+                && consumed > 0) {
+                // Make sure the next char is end, '+', ' ' or '_' so we don't
+                // accept things like "12x3" mid-token.
+                char next = s[consumed];
+                bool boundary = (next == '\0' || next == ' ' || next == '+'
+                                 || next == '_' || next == '\t' || next == ',');
+                if (boundary
+                    && width  >= 640  && width  <= 10000
+                    && height >= 480  && height <= 10000) {
+                    *w = width;
+                    *h = height;
+                    return true;
+                }
+            }
+        }
+        ++s;
+    }
+    return false;
+}
+
 std::vector<DisplayInfo> enumerateDisplays() {
     std::vector<DisplayInfo> displays;
 
     FILE *fp = popen("xrandr --query 2>/dev/null", "r");
     if (!fp) {
-        // Fallback: return default display
         DisplayInfo def;
         def.name = "default";
         def.friendlyName = "default";
@@ -32,78 +65,44 @@ std::vector<DisplayInfo> enumerateDisplays() {
 
     char line[512];
     while (fgets(line, sizeof(line), fp) != nullptr) {
-        // Remove trailing newline
         size_t len = strlen(line);
-        if (len > 0 && line[len - 1] == '\n') {
+        if (len > 0 && line[len - 1] == '\n')
             line[len - 1] = '\0';
-        }
 
-        // Skip lines that don't look like output lines (no "connected")
+        // Only consider lines reporting a connected output.
-        if (strstr(line, "connected") == nullptr) {
+        if (strstr(line, " connected") == nullptr)
             continue;
-        }
 
-        // Parse: <name> connected [primary] <resolution>
+        // Extract the output name (first whitespace-delimited token).
         char name[128] = {};
-        char resolution[64] = {};
-        int isPrimary = 0;
-
-        // Extract name (first token before space)
         char *space = strchr(line, ' ');
         if (!space) continue;
-        size_t nameLen = space - line;
+        size_t nameLen = static_cast<size_t>(space - line);
         if (nameLen >= sizeof(name)) nameLen = sizeof(name) - 1;
         memcpy(name, line, nameLen);
         name[nameLen] = '\0';
 
-        // Check if "primary" is in the line
+        const bool isPrimary = (strstr(line, " primary") != nullptr);
-        if (strstr(line, "primary") != nullptr) {
-            isPrimary = 1;
-        }
-
-        // Extract resolution: look for pattern like "1920x1080"
-        char *res = strstr(line, "1280x720");
-        if (!res) res = strstr(line, "1920x1080");
-        if (!res) res = strstr(line, "2560x1440");
-        if (!res) res = strstr(line, "3840x2160");
-        if (!res) {
-            // More general: look for digits followed by 'x' and more digits
-            res = line;
-            while (*res) {
-                if (isdigit(*res)) {
-                    char *xpos = strchr(res, 'x');
-                    if (xpos && isdigit(xpos[1])) {
-                        break;
-                    }
-                }
-                res++;
-            }
-            if (!*res) continue;
-        }
 
+        // Search for the resolution AFTER the name token so we don't pick up
+        // digits embedded in names like "DP-1" or "eDP-1".
+        const char *afterName = space;
         int w = 0, h = 0;
-        if (sscanf(res, "%dx%d", &w, &h) != 2) {
+        if (!parseResolution(afterName, &w, &h))
             continue;
-        }
-
-        // Only add if we have valid dimensions
-        if (w <= 0 || h <= 0) {
-            continue;
-        }
 
         DisplayInfo info;
-        info.name = std::string(name);
+        info.name         = std::string(name);
         info.friendlyName = std::string(name);
-        info.width = w;
+        info.width        = w;
-        info.height = h;
+        info.height       = h;
-        info.isPrimary = isPrimary != 0;
+        info.isPrimary    = isPrimary;
 
         displays.push_back(info);
     }
 
     pclose(fp);
 
-    // If xrandr returned nothing, fallback to default
     if (displays.empty()) {
         DisplayInfo def;
         def.name = "default";