Fixes git log paging with merge commits

src/git/git.ts

@@ -724,13 +724,14 @@ export namespace Git {
 			`--format=${GitLogParser.defaultFormat}`,
 			'--full-history',
 			`-M${similarityThreshold == null ? '' : `${similarityThreshold}%`}`,
+			'-m',
 		];
 		if (limit && !reverse) {
 			params.push(`-n${limit}`);
 		}
 
-		if (merges) {
-			params.push('-m');
+		if (!merges) {
+			params.push('--first-parent');
 		}
 
 		if (authors) {

src/git/parsers/logParser.ts

@@ -178,7 +178,14 @@ export class GitLogParser {
 					// 'f': // files
 					// Skip the blank line git adds before the files
 					next = lines.next();
-					if (next.done || next.value === '</f>') break;
+					if (next.done || next.value === '</f>') {
+						// If there are no files returned, we end up skipping the commit, so reduce our truncationCount to ensure accurate truncation detection
+						if (truncationCount) {
+							truncationCount--;
+						}
+
+						break;
+					}
 
 					while (true) {
 						next = lines.next();